Carbon dioxide

Formula: CO₂
Molecular weight: 44.0095
IUPAC Standard InChI: InChI=1S/CO2/c2-1-3
IUPAC Standard InChIKey: CURLTUGMZLYLDI-UHFFFAOYSA-N
CAS Registry Number: 124-38-9
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Isotopologues:
- Carbon dioxide (¹²C¹⁶O₂)
Other names: Carbon oxide (CO2); Carbonic acid, gas; Carbonic anhydride; Dry ice; CO2; Anhydride carbonique; Carbonica; Kohlendioxyd; Kohlensaure; UN 1013; UN 1845; UN 2187; Cardice; Dricold; Drikold; Carbonic acid anhydride; Khladon 744; R 744
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Information on this page:
Other data available:
- Reaction thermochemistry data: reactions 51 to 100, reactions 101 to 143
- Henry's Law data
- Mass spectrum (electron ionization)
- Fluid Properties
Data at other public NIST sites:
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Gas phase thermochemistry data

Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-94.051 ± 0.031	kcal/mol	Review	Cox, Wagman, et al., 1984	CODATA Review value
Δ_fH°_gas	-94.054	kcal/mol	Review	Chase, 1998	Data last reviewed in September, 1965
Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	51.0958 ± 0.0024	cal/mol*K	Review	Cox, Wagman, et al., 1984	CODATA Review value
S°_{gas,1 bar}	51.097	cal/mol*K	Review	Chase, 1998	Data last reviewed in September, 1965

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
C_p = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.

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View table.

Temperature (K)	298. to 1200.	1200. to 6000.
A	5.974511	13.90210
B	13.19000	0.650113
C	-8.052431	-0.117660
D	1.899711	0.009284
E	-0.032657	-1.540941
F	-96.46451	-101.7970
G	54.55141	63.00490
H	-94.05411	-94.05411
Reference	Chase, 1998	Chase, 1998
Comment	Data last reviewed in September, 1965	Data last reviewed in September, 1965

Phase change data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Quantity	Value	Units	Method	Reference	Comment
T_triple	216.58	K	N/A	Marsh, 1987	Uncertainty assigned by TRC = 0.008 K; recommended as fixed point for thermometery; TRC
T_triple	216.58	K	N/A	Angus, Armstrong, et al., 1976	Uncertainty assigned by TRC = 0.03 K; TRC
Quantity	Value	Units	Method	Reference	Comment
P_triple	5.117	atm	N/A	Angus, Armstrong, et al., 1976	Uncertainty assigned by TRC = 0.005 atm; TRC
Quantity	Value	Units	Method	Reference	Comment
T_c	304.18	K	N/A	Suehiro, Nakajima, et al., 1996	Uncertainty assigned by TRC = 0.04 K; TRC
T_c	304.1	K	N/A	Weber, 1989	Uncertainty assigned by TRC = 0.1 K; TRC
T_c	304.35	K	N/A	Li and Kiran, 1988	Uncertainty assigned by TRC = 0.4 K; TRC
T_c	304.200	K	N/A	Morrison, 1981	Uncertainty assigned by TRC = 0.02 K; TRC
T_c	304.23	K	N/A	Efremova and Shvarts, 1972	Visual, agreement with literature evidence of sample purity; TRC
Quantity	Value	Units	Method	Reference	Comment
P_c	72.83	atm	N/A	Suehiro, Nakajima, et al., 1996	Uncertainty assigned by TRC = 0.15 atm; TRC
P_c	72.44	atm	N/A	Li and Kiran, 1988	Uncertainty assigned by TRC = 0.49 atm; TRC
P_c	72.860	atm	N/A	Angus, Armstrong, et al., 1976	Uncertainty assigned by TRC = 0.005 atm; TRC
Quantity	Value	Units	Method	Reference	Comment
V_c	0.0919	l/mol	N/A	Li and Kiran, 1988	Uncertainty assigned by TRC = 0.001 l/mol; TRC
Quantity	Value	Units	Method	Reference	Comment
ρ_c	10.6	mol/l	N/A	Suehiro, Nakajima, et al., 1996	Uncertainty assigned by TRC = 0.05 mol/l; TRC
ρ_c	10.590	mol/l	N/A	Angus, Armstrong, et al., 1976	Uncertainty assigned by TRC = 0.007 mol/l; TRC
ρ_c	10.8	mol/l	N/A	Andrizhievskii and Chernova, 1970	Uncertainty assigned by TRC = 0.2 mol/l; TRC
ρ_c	10.64	mol/l	N/A	Lowry and Erickson, 1927	Uncertainty assigned by TRC = 0.034 mol/l; from a plot of (DN(liq) + DN(g))/2 based on exp. measurement and extrapolated to 31.0 deg C; TRC

Enthalpy of vaporization

Δ_vapH (kcal/mol)	Temperature (K)	Method	Reference	Comment
3.99	288.	A	Stephenson and Malanowski, 1987	Based on data from 273. to 304. K.; AC
3.92	258.	A	Stephenson and Malanowski, 1987	Based on data from 216. to 273. K.; AC
3.94	282.	N/A	Boublík and Aim, 1972	Based on data from 267. to 303. K.; AC

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)

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Temperature (K)	A	B	C	Reference	Comment
154.26 to 195.89	6.80657	1301.679	-3.494	Giauque and Egan, 1937	Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

Δ_subH (kcal/mol)	Temperature (K)	Method	Reference	Comment
6.24	207.	A	Stephenson and Malanowski, 1987	Based on data from 198. to 216. K.; AC
6.50 ± 0.1	70. to 102.	LE	Bryson, Cazcarra, et al., 1974	AC
6.19	188.	N/A	Ambrose, 1956	Based on data from 179. to 198. K.; AC
6.29	167.	A	Stull, 1947	Based on data from 139. to 195. K.; AC
6.02	195.	N/A	Giauque and Egan, 1937, 2	Based on data from 154. to 196. K.; AC

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Data compiled as indicated in comments:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Reactions 1 to 50

+ Carbon dioxide = ( • )

By formula: O₂⁺ + CO₂ = (O₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.8 ± 0.9	kcal/mol	AVG	N/A	Average of 4 out of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.5	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	18.9	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=9.80 kcal/mol; M
Δ_rS°	20.7	cal/mol*K	N/A	Dotan, Davidson, et al., 1978	gas phase; switching reaction(O2+)O2, Entropy change calculated or estimated; Conway and Janik, 1970; M
Δ_rS°	20.	cal/mol*K	N/A	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	4.4	kcal/mol	DT	Rakshit and Warneck, 1981	gas phase; M
Δ_rG°	4.3	kcal/mol	FA	Dotan, Davidson, et al., 1978	gas phase; switching reaction(O2+)O2, Entropy change calculated or estimated; Conway and Janik, 1970; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.4	600.	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M

+ Carbon dioxide = ( • )

By formula: CO₂⁺ + CO₂ = (CO₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16. ± 1.	kcal/mol	AVG	N/A	Average of 7 out of 10 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	18.6	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=15.9 kcal/mol; M
Δ_rS°	19.5	cal/mol*K	DT	Van Koppen, Kemper, et al., 1983	gas phase; M
Δ_rS°	22.8	cal/mol*K	PHPMS	Headley, Mason, et al., 1982	gas phase; M
Δ_rS°	21.1	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

O^- + Carbon dioxide = (O^- • )

By formula: O^- + CO₂ = (O^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	48. ± 10.	kcal/mol	AVG	N/A	Average of 8 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	48.0 ± 5.0	kcal/mol	IMRE	Adams and Bohme, 1970	gas phase; O₃^- + CO₂ <=> CO₃^- + O₂; B

+ Carbon dioxide = ( • )

By formula: I^- + CO₂ = (I^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.7 ± 1.8	kcal/mol	N/A	Piani, Becucci, et al., 2008	gas phase; Stated electron affinity is the Vertical Detachment Energy; B
Δ_rH°	4.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	3.20	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	5.60 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	13.4	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Δ_rS°	18.2	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	0.80 ± 0.10	kcal/mol	TDAs	Banic and Iribarne, 1985	gas phase; B,M
Δ_rG°	0.40 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

+ Carbon dioxide = ( • )

By formula: O₂^- + CO₂ = (O₂^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.00 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Δ_rH°	17.7 ± 1.8	kcal/mol	IMRE	Pack and Phelps, 1966	gas phase; Corrected with more recent EA(O2) = 0.45 eV; B,M
Δ_rH°	25.4 ± 4.6	kcal/mol	PDis	Vestal and Mauclaire, 1977	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Δ_rS°	21.	cal/mol*K	DT	Pack and Phelps, 1966	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	11.7 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	12.2 ± 1.2	kcal/mol	IMRE	Pack and Phelps, 1966	gas phase; Corrected with more recent EA(O2) = 0.45 eV; B
Δ_rG°	10.0	kcal/mol	FA	Adams and Bohme, 1970	gas phase; switching reaction(O2-)O2; Conway and Nesbit, 1968; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
12.9	296.	FA	Fehsenfeld and Ferguson, 1974	gas phase; switching reaction(O2-)H2O; Arshadi and Kebarle, 1970; M

+ Carbon dioxide = ( • )

By formula: F^- + CO₂ = (F^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	32.07	kcal/mol	N/A	Arnold, Bradforth, et al., 1995, 2	gas phase; B
Δ_rH°	32.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	31.7 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M
Δ_rH°	33.0 ± 3.0	kcal/mol	IMRE	McMahon and Northcott, 1978	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.7	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Δ_rS°	24.	cal/mol*K	N/A	Larson and McMahon, 1985	gas phase; switching reaction,Thermochemical ladder(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	24.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	24.5 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M
Δ_rG°	11.6	kcal/mol	FA	Spears and Ferguson, 1973	gas phase; DG>; M

+ Carbon dioxide = ( • )

By formula: Cl^- + CO₂ = (Cl^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.80 ± 0.50	kcal/mol	PDis	Arnold, Bradforth, et al., 1995, 2	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B
Δ_rH°	7.60	kcal/mol	TDEq	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Δ_rH°	8.00 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	19.6	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.10	kcal/mol	TDEq	Hiraoka, Shoda, et al., 1986	gas phase; B
Δ_rG°	2.10 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (I^- • 2CO₂) + CO₂ = (I^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.20	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.7 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.6 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.4	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.6 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (I^- • 4CO₂) + CO₂ = (I^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.70	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (I^- • CO₂) + CO₂ = (I^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.7 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	2.60	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (I^- • 5CO₂) + CO₂ = (I^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.80	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	4.2	kcal/mol	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.	cal/mol*K	N/A	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M

( • Carbon dioxide ) + = ( • • )

By formula: (Na⁺ • CO₂) + H₂O = (Na⁺ • H₂O • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.7	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M
Δ_rH°	22.9	kcal/mol	FA	Perry, Rowe, et al., 1980	gas phase; From thermochemical cycle(Na+) 2H2O; Dzidic and Kebarle, 1970, Peterson, Mark, et al., 1984; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.3	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M
Δ_rS°	25.6	cal/mol*K	FA	Perry, Rowe, et al., 1980	gas phase; From thermochemical cycle(Na+) 2H2O; Dzidic and Kebarle, 1970, Peterson, Mark, et al., 1984; M

CHO₂⁺ + Carbon dioxide = (CHO₂⁺ • )

By formula: CHO₂⁺ + CO₂ = (CHO₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.8	kcal/mol	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rH°	18.0	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rH°	19.1	kcal/mol	PHPMS	Jennings, Headley, et al., 1982	gas phase; M
Δ_rH°	20.1	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.6	cal/mol*K	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rS°	22.2	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	27.1	cal/mol*K	PHPMS	Jennings, Headley, et al., 1982	gas phase; M
Δ_rS°	24.2	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (I^- • 3CO₂) + CO₂ = (I^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.80	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.0 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

+ Carbon dioxide = ( • )

By formula: NO₂^- + CO₂ = (NO₂^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.30 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Δ_rH°	9.30 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Δ_rS°	24.2	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.1 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	2.00 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

+ Carbon dioxide = ( • )

By formula: NO^- + CO₂ = (NO^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.5 ± 0.3	kcal/mol	DT	Illies, 1988	gas phase; Δ_rH(0 K)=8.60 kcal/mol; M
Δ_rH°	7.7 ± 0.4	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Δ_rH°	13.8	kcal/mol	FA	Dunkin, Fehsenfeld, et al., 1971	gas phase; switching reaction(NO+)NO, Δ_rH<; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.0	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=8.60 kcal/mol; M
Δ_rS°	13.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • Carbon dioxide ) + = ( • 2)

By formula: (Br^- • CO₂) + CO₂ = (Br^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	6.0 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (CO₂⁺ • CO₂) + CO₂ = (CO₂⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.6 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	8.3	kcal/mol	EI	Cameron, Aitken, et al., 1994	gas phase; M
Δ_rH°	3.3	kcal/mol	PI	Linn and Ng, 1981	gas phase; M
Δ_rH°	6.0	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	14.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	24.0	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

+ Carbon dioxide = ( • )

By formula: Br^- + CO₂ = (Br^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.3 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995, 2	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B
Δ_rH°	6.7 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	16.5	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.8 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (Cl^- • 2CO₂) + CO₂ = (Cl^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.8 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rH°	6.80	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.4	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.1 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	0.10	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (Cl^- • CO₂) + CO₂ = (Cl^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rH°	7.20	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.8	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	1.00	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B

+ Carbon dioxide = ( • )

By formula: H₃O⁺ + CO₂ = (H₃O⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.3	kcal/mol	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rH°	15.3	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rH°	14.4	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.2	cal/mol*K	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rS°	24.6	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	20.7	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

( • 2 • Carbon dioxide ) + = ( • 3 • )

By formula: (Na⁺ • 2H₂O • CO₂) + H₂O = (Na⁺ • 3H₂O • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.4	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	5.5	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M

( • Carbon dioxide ) + = ( • 2)

By formula: (O₂⁺ • CO₂) + CO₂ = (O₂⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.6 ± 0.5	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	7.5	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change is questionable; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.7	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	15.	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change is questionable; M

( • 3) + Carbon dioxide = ( • • 3)

By formula: (Na⁺ • 3H₂O) + CO₂ = (Na⁺ • CO₂ • 3H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.3	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (Na⁺ • 3CO₂) + CO₂ = (Na⁺ • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.4	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
0.7	310.	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

+ Carbon dioxide = ( • )

By formula: Na⁺ + CO₂ = (Na⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.9	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Δ_rH°	13.7	kcal/mol	FA	Perry, Rowe, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.1	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Δ_rS°	19.8	cal/mol*K	FA	Perry, Rowe, et al., 1980	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.6	310.	DT	Keller and Beyer, 1971	gas phase; low E/N; M

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (I^- • 6CO₂) + CO₂ = (I^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.3 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.90	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B

( • 7 Carbon dioxide ) + = ( • 8)

By formula: (I^- • 7CO₂) + CO₂ = (I^- • 8CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.90	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (Cl^- • 3CO₂) + CO₂ = (Cl^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.40	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; entropy estimated.; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.	cal/mol*K	N/A	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.80	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; entropy estimated.; B

CO₃^- + Carbon dioxide = C₂O₅^-

By formula: CO₃^- + CO₂ = C₂O₅^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.90 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rH°	7.10 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.0 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	0.60 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

HO^- + Carbon dioxide = (HO^- • )

By formula: HO^- + CO₂ = (HO^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	50.9 ± 2.5	kcal/mol	CIDT	Squires, 1992	gas phase; Dissociative protonation threshold at nPrSH, 9 kcal> calc. CIDC(HOCO2-..HSH) = 7:1 HOCO2-; B
Δ_rH°	87.60	kcal/mol	Endo	Hierl and Paulson, 1984	gas phase; Implies ΔHacid = 291.4, anion appears too stable - JEB; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (CO₂⁺ • 2CO₂) + CO₂ = (CO₂⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0	kcal/mol	EI	Cameron, Aitken, et al., 1994	gas phase; M
Δ_rH°	5.1 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	2.8	kcal/mol	PI	Linn and Ng, 1981	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • • Carbon dioxide ) + = ( • 2 • )

By formula: (Na⁺ • H₂O • CO₂) + H₂O = (Na⁺ • 2H₂O • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.4	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.6	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; From thermochemical cycle; Dzidic and Kebarle, 1970; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (F^- • 3CO₂) + CO₂ = (F^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.8 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.2 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (F^- • 4CO₂) + CO₂ = (F^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.6 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.0 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (F^- • 5CO₂) + CO₂ = (F^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.5	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

C₇O₁₅^- + 7 Carbon dioxide = C₈O₁₇^-

By formula: C₇O₁₅^- + 7CO₂ = C₈O₁₇^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; Estimated entropy; single temperature measurement; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; Estimated entropy; single temperature measurement; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (F^- • 2CO₂) + CO₂ = (F^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.6	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.5 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (F^- • CO₂) + CO₂ = (F^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.9 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (O₂^- • 2CO₂) + CO₂ = (O₂^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.3 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.6 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (O₂^- • 3CO₂) + CO₂ = (O₂^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (O₂^- • 4CO₂) + CO₂ = (O₂^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.4	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (O₂^- • 5CO₂) + CO₂ = (O₂^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (O₂^- • 6CO₂) + CO₂ = (O₂^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (O₂^- • CO₂) + CO₂ = (O₂^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.60 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (NO₂^- • 2CO₂) + CO₂ = (NO₂^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.3 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (NO₂^- • 3CO₂) + CO₂ = (NO₂^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (NO₂^- • 4CO₂) + CO₂ = (NO₂^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (NO₂^- • 5CO₂) + CO₂ = (NO₂^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.9 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.1	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Ion clustering data, IR Spectrum, Gas Chromatography, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	13.777 ± 0.001	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	129.2	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	123.3	kcal/mol	N/A	Hunter and Lias, 1998	HL

Electron affinity determinations

EA (eV)	Method	Reference	Comment
-0.599986	EIAE	Knapp, Echt, et al., 1986	Unbound but in -0.3 eV well, from (CO2)n; B
-1.60 ± 0.10	NBIE	Compton, Reinhardt, et al., 1975	B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
13.778 ± 0.002	PE	Wang, Reutt, et al., 1988	LL
13.78	PE	Kimura, Katsumata, et al., 1981	LLK
13.776 ± 0.002	PE	Potts and Fattahallah, 1980	LLK
13. ± 1.	PI	Hitchcock, Brion, et al., 1980	LLK
13.89 ± 0.03	EI	Sahini, Constantin, et al., 1978	LLK
13.79 ± 0.05	EI	Mark and Hille, 1978	LLK
13.77	PI	Jones and Taylor, 1978	LLK
13.777 ± 0.002	PE	Frey, Gotchev, et al., 1977	LLK
13.83 ± 0.05	EI	Bussieres and Marmet, 1977	LLK
13.788	PE	Kronebusch and Berkowitz, 1976	LLK
13.776 ± 0.002	TE	Batten, Taylor, et al., 1976	LLK
13.774 ± 0.003	PI	Parr and Taylor, 1974	LLK
13.9 ± 0.2	EI	Semenov, Volkov, et al., 1973	LLK
13.776 ± 0.008	PI	Parr and Taylor, 1973	LLK
13.78	PE	Natalis, 1973	LLK
13.773 ± 0.002	PI	McCulloh, 1973	LLK
13.80 ± 0.01	PE	Frost, Lee, et al., 1973	LLK
13.788 ± 0.005	PE	Brundle and Turner, 1969	RDSH
13.78 ± 0.01	PE	Eland and Danby, 1968	RDSH
13.77	PE	Spohr and Puttkamer, 1967	RDSH
13.75 ± 0.05	EI	Carette, 1967	RDSH
13.767 ± 0.003	PI	Nakata, Watanabe, et al., 1965	RDSH
13.77 ± 0.03	S	Tanaka, Jursa, et al., 1960	RDSH
13.773	PE	Eland and Berkowitz, 1977	Vertical value; LLK
13.78	PE	Benoit and Harrison, 1977	Vertical value; LLK
13.78	PE	Schweig and Thiel, 1974	Vertical value; LLK
13.79	PE	Potts and Williams, 1974	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C⁺	25. ± 2.	O₂	PI	Hitchcock, Brion, et al., 1980	LLK
C⁺	22.7 ± 0.2	O₂	EI	Bussieres and Marmet, 1977	LLK
C⁺	27.8 ± 0.1	2O	EI	Bussieres and Marmet, 1977	LLK
C⁺	24.6 ± 1.0	O₂	EI	Crowe and McConkey, 1974	LLK
C⁺	28.4 ± 0.6	2O	EI	Cuthbert, Farren, et al., 1968	RDSH
C⁺	14.2 ± 0.5	2O	EI	Cuthbert, Farren, et al., 1968	RDSH
C⁺	23.2 ± 0.5	O₂	EI	Cuthbert, Farren, et al., 1968	RDSH
CO⁺	19. ± 2.	O	PI	Hitchcock, Brion, et al., 1980	LLK
CO⁺	19.466	O	PE	Eland and Berkowitz, 1977, 2	LLK
CO⁺	19.42 ± 0.075	O	EI	Bussieres and Marmet, 1977	LLK
CO⁺	19.466	O	PE	Kronebusch and Berkowitz, 1976	LLK
CO⁺	20.9 ± 1.0	O	EI	Crowe and McConkey, 1974	LLK
CO⁺	29.0	O	PI	Samson and Gardner, 1973	LLK
O⁺	19. ± 1.	CO	PI	Hitchcock, Brion, et al., 1980	LLK
O⁺	19.071	CO	PE	Eland and Berkowitz, 1977, 2	LLK
O⁺	19.05 ± 0.05	CO	EI	Bussieres and Marmet, 1977	LLK
O⁺	19.067	CO	PE	Kronebusch and Berkowitz, 1976	LLK
O⁺	19.393 ± 0.008	?	PI	Parr and Taylor, 1974	LLK
O⁺	22.6 ± 1.0	CO	EI	Crowe and McConkey, 1974	LLK
O⁺	19.10 ± 0.01	CO	PI	Dibeler and Walker, 1967	RDSH

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Gas Chromatography, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
RCD - Robert C. Dunbar

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

+ Carbon dioxide = ( • )

By formula: Br^- + CO₂ = (Br^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.3 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995, 2	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B
Δ_rH°	6.7 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	16.5	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.8 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (Br^- • CO₂) + CO₂ = (Br^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	6.0 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (Br^- • 2CO₂) + CO₂ = (Br^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (Br^- • 3CO₂) + CO₂ = (Br^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (Br^- • 4CO₂) + CO₂ = (Br^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (Br^- • 5CO₂) + CO₂ = (Br^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (Br^- • 6CO₂) + CO₂ = (Br^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 7 Carbon dioxide ) + = ( • 8)

By formula: (Br^- • 7CO₂) + CO₂ = (Br^- • 8CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.7 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 8 Carbon dioxide ) + = ( • 9)

By formula: (Br^- • 8CO₂) + CO₂ = (Br^- • 9CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.8 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 9 Carbon dioxide ) + = ( • 10)

By formula: (Br^- • 9CO₂) + CO₂ = (Br^- • 10CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.8 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 10 Carbon dioxide ) + = ( • 11)

By formula: (Br^- • 10CO₂) + CO₂ = (Br^- • 11CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.5 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

+ Carbon dioxide = ( • )

By formula: CHO⁺ + CO₂ = (CHO⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.6	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.4	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

( • Carbon dioxide ) + = ( • 2)

By formula: (CHO⁺ • CO₂) + CO₂ = (CHO⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.7	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (CHO⁺ • 2CO₂) + CO₂ = (CHO⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.9	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.7	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (CHO⁺ • 3CO₂) + CO₂ = (CHO⁺ • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.4	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.	cal/mol*K	N/A	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M

CHO₂⁺ + Carbon dioxide = (CHO₂⁺ • )

By formula: CHO₂⁺ + CO₂ = (CHO₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.8	kcal/mol	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rH°	18.0	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rH°	19.1	kcal/mol	PHPMS	Jennings, Headley, et al., 1982	gas phase; M
Δ_rH°	20.1	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.6	cal/mol*K	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rS°	22.2	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	27.1	cal/mol*K	PHPMS	Jennings, Headley, et al., 1982	gas phase; M
Δ_rS°	24.2	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

(CHO₂⁺ • Carbon dioxide ) + = (CHO₂⁺ • 2)

By formula: (CHO₂⁺ • CO₂) + CO₂ = (CHO₂⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.9	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

(CHO₂⁺ • 2 Carbon dioxide ) + = (CHO₂⁺ • 3)

By formula: (CHO₂⁺ • 2CO₂) + CO₂ = (CHO₂⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.9	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.	cal/mol*K	N/A	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M

( • 4294967295 Carbon dioxide ) + =

By formula: (CHO₂^- • 4294967295CO₂) + CO₂ = CHO₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.6 ± 2.3	kcal/mol	N/A	Caldwell, Renneboog, et al., 1989	gas phase; B

+ Carbon dioxide = ( • )

By formula: CH₃⁺ + CO₂ = (CH₃⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	49.4	kcal/mol	PHPMS	McMahon, Heinis, et al., 1988	gas phase; switching reaction(CH3+)N2, Entropy change calculated or estimated, uses MCA(N2) = 48.3 kcal/mol; Foster, Williamson, et al., 1974; M

CH₆N⁺ + Carbon dioxide = (CH₆N⁺ • )

By formula: CH₆N⁺ + CO₂ = (CH₆N⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.2	kcal/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.4	cal/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

CN^- + Carbon dioxide = (CN^- • )

By formula: CN^- + CO₂ = (CN^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.30 ± 0.80	kcal/mol	TDAs	Larson, Szulejko, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	31.5	cal/mol*K	PHPMS	Larson, Szulejko, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	7.90 ± 0.20	kcal/mol	TDAs	Larson, Szulejko, et al., 1988	gas phase; B

+ Carbon dioxide = ( • )

By formula: CO₂⁺ + CO₂ = (CO₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16. ± 1.	kcal/mol	AVG	N/A	Average of 7 out of 10 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	18.6	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=15.9 kcal/mol; M
Δ_rS°	19.5	cal/mol*K	DT	Van Koppen, Kemper, et al., 1983	gas phase; M
Δ_rS°	22.8	cal/mol*K	PHPMS	Headley, Mason, et al., 1982	gas phase; M
Δ_rS°	21.1	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

( • Carbon dioxide ) + = ( • 2)

By formula: (CO₂⁺ • CO₂) + CO₂ = (CO₂⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.6 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	8.3	kcal/mol	EI	Cameron, Aitken, et al., 1994	gas phase; M
Δ_rH°	3.3	kcal/mol	PI	Linn and Ng, 1981	gas phase; M
Δ_rH°	6.0	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	14.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	24.0	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (CO₂⁺ • 2CO₂) + CO₂ = (CO₂⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0	kcal/mol	EI	Cameron, Aitken, et al., 1994	gas phase; M
Δ_rH°	5.1 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	2.8	kcal/mol	PI	Linn and Ng, 1981	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.1	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (CO₂⁺ • 3CO₂) + CO₂ = (CO₂⁺ • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.8 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.7	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (CO₂⁺ • 4CO₂) + CO₂ = (CO₂⁺ • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.3 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.7	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (CO₂⁺ • 5CO₂) + CO₂ = (CO₂⁺ • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.0	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.	cal/mol*K	N/A	Hiraoka, Nakajima, et al., 1988	gas phase; Entropy change calculated or estimated; M

CO₃^- + Carbon dioxide = C₂O₅^-

By formula: CO₃^- + CO₂ = C₂O₅^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.90 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rH°	7.10 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.0 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	0.60 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

CO₃^- + Carbon dioxide = (CO₃^- • )

By formula: CO₃^- + CO₂ = (CO₃^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.9 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	16.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • Carbon dioxide ) + = (CO₃^- • 2)

By formula: (CO₃^- • CO₂) + CO₂ = (CO₃^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.7 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • 2 Carbon dioxide ) + = (CO₃^- • 3)

By formula: (CO₃^- • 2CO₂) + CO₂ = (CO₃^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.5 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • 3 Carbon dioxide ) + = (CO₃^- • 4)

By formula: (CO₃^- • 3CO₂) + CO₂ = (CO₃^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • 4 Carbon dioxide ) + = (CO₃^- • 5)

By formula: (CO₃^- • 4CO₂) + CO₂ = (CO₃^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.8 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • 5 Carbon dioxide ) + = (CO₃^- • 6)

By formula: (CO₃^- • 5CO₂) + CO₂ = (CO₃^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.7 ± 0.2	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M

(CO₃^- • 6 Carbon dioxide ) + = (CO₃^- • 7)

By formula: (CO₃^- • 6CO₂) + CO₂ = (CO₃^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.45	kcal/mol	PHPMS	Hiraoka and Yamabe, 1992	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.	cal/mol*K	N/A	Hiraoka and Yamabe, 1992	gas phase; Entropy change calculated or estimated; M

( • 4294967295 Carbon dioxide ) + =

By formula: (C₂H₂O₂^- • 4294967295CO₂) + CO₂ = C₂H₂O₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	61.7 ± 2.7	kcal/mol	CIDT	Wenthold and Squires, 1994	gas phase; B

( • 4294967295 Carbon dioxide ) + =

By formula: (C₂H₃O₂^- • 4294967295CO₂) + CO₂ = C₂H₃O₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	59.7 ± 2.5	kcal/mol	CIDC	Wenthold and Squires, 1994	gas phase; B

C₂H₈N⁺ + Carbon dioxide = (C₂H₈N⁺ • )

By formula: C₂H₈N⁺ + CO₂ = (C₂H₈N⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.2	kcal/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.8	cal/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

C₂O₅^- + 2 Carbon dioxide = C₃O₇^-

By formula: C₂O₅^- + 2CO₂ = C₃O₇^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.4 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

C₃O₇^- + 3 Carbon dioxide = C₄O₉^-

By formula: C₃O₇^- + 3CO₂ = C₄O₉^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

C₄O₉^- + 4 Carbon dioxide = C₅O₁₁^-

By formula: C₄O₉^- + 4CO₂ = C₅O₁₁^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

C₅O₁₁^- + 5 Carbon dioxide = C₆O₁₃^-

By formula: C₅O₁₁^- + 5CO₂ = C₆O₁₃^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

C₆O₁₃^- + 6 Carbon dioxide = C₇O₁₅^-

By formula: C₆O₁₃^- + 6CO₂ = C₇O₁₅^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.9 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

C₇O₁₅^- + 7 Carbon dioxide = C₈O₁₇^-

By formula: C₇O₁₅^- + 7CO₂ = C₈O₁₇^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; Estimated entropy; single temperature measurement; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; Estimated entropy; single temperature measurement; B

(Ca⁺² • 4 Carbon dioxide • ) + = (Ca⁺² • 5 • )

By formula: (Ca⁺² • 4CO₂ • CCaO₃) + CO₂ = (Ca⁺² • 5CO₂ • CCaO₃)

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
7.6	296.	FA	Spears and Fehsenfeld, 1972	gas phase; M

(Ca⁺² • 5 Carbon dioxide ) + = (Ca⁺² • 6)

By formula: (Ca⁺² • 5CO₂) + CO₂ = (Ca⁺² • 6CO₂)

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
8.1	296.	FA	Spears and Fehsenfeld, 1972	gas phase; M

+ Carbon dioxide = ( • )

By formula: Cl^- + CO₂ = (Cl^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.80 ± 0.50	kcal/mol	PDis	Arnold, Bradforth, et al., 1995, 2	gas phase; Affinity: shift in apparent EA from lesser-solvated ion. Ignores any neutral-neutral bond.; B
Δ_rH°	7.60	kcal/mol	TDEq	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Δ_rH°	8.00 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	19.6	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.10	kcal/mol	TDEq	Hiraoka, Shoda, et al., 1986	gas phase; B
Δ_rG°	2.10 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (Cl^- • CO₂) + CO₂ = (Cl^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rH°	7.20	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.8	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	1.00	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (Cl^- • 2CO₂) + CO₂ = (Cl^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.8 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rH°	6.80	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.4	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.1 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	0.10	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (Cl^- • 3CO₂) + CO₂ = (Cl^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.40	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; entropy estimated.; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.	cal/mol*K	N/A	Hiraoka, Shoda, et al., 1986	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.80	kcal/mol	TDAs	Hiraoka, Shoda, et al., 1986	gas phase; entropy estimated.; B

+ Carbon dioxide = ( • )

By formula: Cs⁺ + CO₂ = (Cs⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.2	kcal/mol	DT	McKnight and Sawina, 1972	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	14.3	cal/mol*K	DT	McKnight and Sawina, 1972	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
2.4	301.	HPMS	Banic and Iribarne, 1985	gas phase; electric fields; M

( • ) + Carbon dioxide = ( • • )

By formula: (Cs⁺ • H₂O) + CO₂ = (Cs⁺ • CO₂ • H₂O)

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
1.2	301.	HPMS	Banic and Iribarne, 1985	gas phase; electric fields; M

+ Carbon dioxide = ( • )

By formula: F^- + CO₂ = (F^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	32.07	kcal/mol	N/A	Arnold, Bradforth, et al., 1995, 2	gas phase; B
Δ_rH°	32.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	31.7 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M
Δ_rH°	33.0 ± 3.0	kcal/mol	IMRE	McMahon and Northcott, 1978	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.7	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Δ_rS°	24.	cal/mol*K	N/A	Larson and McMahon, 1985	gas phase; switching reaction,Thermochemical ladder(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	24.3 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	24.5 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M
Δ_rG°	11.6	kcal/mol	FA	Spears and Ferguson, 1973	gas phase; DG>; M

( • Carbon dioxide ) + = ( • 2)

By formula: (F^- • CO₂) + CO₂ = (F^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.9 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (F^- • 2CO₂) + CO₂ = (F^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.6	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.5 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (F^- • 3CO₂) + CO₂ = (F^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.8 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.2 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (F^- • 4CO₂) + CO₂ = (F^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.6 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.0 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (F^- • 5CO₂) + CO₂ = (F^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.5	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (F^- • 6CO₂) + CO₂ = (F^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.9	kcal/mol	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.	cal/mol*K	N/A	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M

+ Carbon dioxide = ( • )

By formula: Fe⁺ + CO₂ = (Fe⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.3 ± 1.0	kcal/mol	CIDT	Rodgers and Armentrout, 2000	RCD

HO^- + Carbon dioxide = (HO^- • )

By formula: HO^- + CO₂ = (HO^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	50.9 ± 2.5	kcal/mol	CIDT	Squires, 1992	gas phase; Dissociative protonation threshold at nPrSH, 9 kcal> calc. CIDC(HOCO2-..HSH) = 7:1 HOCO2-; B
Δ_rH°	87.60	kcal/mol	Endo	Hierl and Paulson, 1984	gas phase; Implies ΔHacid = 291.4, anion appears too stable - JEB; B

+ Carbon dioxide = ( • )

By formula: HO^- + CO₂ = (HO^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	88.	kcal/mol	CID	Hierl and Paulson, 1984	gas phase; M

+ Carbon dioxide = ( • )

By formula: H₃O⁺ + CO₂ = (H₃O⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14.3	kcal/mol	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rH°	15.3	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rH°	14.4	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.2	cal/mol*K	PHPMS	Szulejko and McMahon, 1992	gas phase; M
Δ_rS°	24.6	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Δ_rS°	20.7	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; M

( • Carbon dioxide ) + = ( • 2)

By formula: (H₃O⁺ • CO₂) + CO₂ = (H₃O⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.4	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.5	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (H₃O⁺ • 2CO₂) + CO₂ = (H₃O⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.5	kcal/mol	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.9	cal/mol*K	PHPMS	Hiraoka, Shoda, et al., 1986	gas phase; M

+ Carbon dioxide = ( • )

By formula: H₄N⁺ + CO₂ = (H₄N⁺ • CO₂)

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
2.3	296.	FA	Spears and Fehsenfeld, 1972	gas phase; M

( • 2) + Carbon dioxide = ( • • 2)

By formula: (H₄N⁺ • 2H₂O) + CO₂ = (H₄N⁺ • CO₂ • 2H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.3	kcal/mol	HPMS	Banic and Iribarne, 1985	gas phase; electric fields; M

+ Carbon dioxide = ( • )

By formula: I^- + CO₂ = (I^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.7 ± 1.8	kcal/mol	N/A	Piani, Becucci, et al., 2008	gas phase; Stated electron affinity is the Vertical Detachment Energy; B
Δ_rH°	4.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	3.20	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	5.60 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	13.4	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Δ_rS°	18.2	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Δ_rG°	0.80 ± 0.10	kcal/mol	TDAs	Banic and Iribarne, 1985	gas phase; B,M
Δ_rG°	0.40 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (I^- • CO₂) + CO₂ = (I^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.7 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Δ_rH°	2.60	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.3	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.7 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (I^- • 2CO₂) + CO₂ = (I^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.20	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.7 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.6 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.4	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.6 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (I^- • 3CO₂) + CO₂ = (I^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.80	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.0 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (I^- • 4CO₂) + CO₂ = (I^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.70	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	3.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	4.3 ± 1.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.4 ± 2.0	kcal/mol	TDAs	Hiraoka, Mizuse, et al., 1987	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (I^- • 5CO₂) + CO₂ = (I^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.80	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B
Δ_rH°	4.2	kcal/mol	PHPMS	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.	cal/mol*K	N/A	Hiraoka, Mizuse, et al., 1987	gas phase; Entropy change calculated or estimated; M

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (I^- • 6CO₂) + CO₂ = (I^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.3 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.90	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B

( • 7 Carbon dioxide ) + = ( • 8)

By formula: (I^- • 7CO₂) + CO₂ = (I^- • 8CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B
Δ_rH°	1.90	kcal/mol	N/A	Gomez, Taylor, et al., 2002	gas phase; EA=Vertical Detachment Energy. Affinity is stepwise difference in EAs.; B

( • 8 Carbon dioxide ) + = ( • 9)

By formula: (I^- • 8CO₂) + CO₂ = (I^- • 9CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.8 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 9 Carbon dioxide ) + = ( • 10)

By formula: (I^- • 9CO₂) + CO₂ = (I^- • 10CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.9 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 10 Carbon dioxide ) + = ( • 11)

By formula: (I^- • 10CO₂) + CO₂ = (I^- • 11CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.0 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 11 Carbon dioxide ) + = ( • 12)

By formula: (I^- • 11CO₂) + CO₂ = (I^- • 12CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.6 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

( • 12 Carbon dioxide ) + = ( • 13)

By formula: (I^- • 12CO₂) + CO₂ = (I^- • 13CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.1 ± 2.0	kcal/mol	PDis	Arnold, Bradforth, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

+ Carbon dioxide = ( • )

By formula: K⁺ + CO₂ = (K⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.5	kcal/mol	HPMS	Castleman and Keesee, 1981	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	15.2	cal/mol*K	HPMS	Castleman and Keesee, 1981	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
3.7	310.	DT	Keller and Beyer, 1971, 2	gas phase; low E/N; M

Kr⁺ + Carbon dioxide = (Kr⁺ • )

By formula: Kr⁺ + CO₂ = (Kr⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.9 ± 0.7	kcal/mol	SIFT	Praxmarer, Jordan, et al., 1993	gas phase; switching reaction(Kr+)Kr; Wadt, 1978, Radzig and Smirnov, 1985; M

+ Carbon dioxide = ( • )

By formula: Mg⁺ + CO₂ = (Mg⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13.8 ± 1.4	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • Carbon dioxide ) + = ( • 2)

By formula: (Mg⁺ • CO₂) + CO₂ = (Mg⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.5 ± 0.7	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (Mg⁺ • 2CO₂) + CO₂ = (Mg⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.6 ± 1.4	kcal/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

+ Carbon dioxide = ( • )

By formula: NO^- + CO₂ = (NO^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.5 ± 0.3	kcal/mol	DT	Illies, 1988	gas phase; Δ_rH(0 K)=8.60 kcal/mol; M
Δ_rH°	7.7 ± 0.4	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Δ_rH°	13.8	kcal/mol	FA	Dunkin, Fehsenfeld, et al., 1971	gas phase; switching reaction(NO+)NO, Δ_rH<; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.0	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=8.60 kcal/mol; M
Δ_rS°	13.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • Carbon dioxide ) + = ( • 2)

By formula: (NO^- • CO₂) + CO₂ = (NO^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.4 ± 0.4	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.1	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (NO^- • 2CO₂) + CO₂ = (NO^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 0.4	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.8	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (NO^- • 3CO₂) + CO₂ = (NO^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.7 ± 0.3	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.4	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (NO^- • 4CO₂) + CO₂ = (NO^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 0.3	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	26.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (NO^- • 5CO₂) + CO₂ = (NO^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.0	kcal/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	28.	cal/mol*K	N/A	Hiraoka and Yamabe, 1991	gas phase; Entropy change calculated or estimated; M

+ Carbon dioxide = ( • )

By formula: NO₂^- + CO₂ = (NO₂^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.30 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Δ_rH°	9.30 ± 0.10	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Δ_rS°	24.2	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.1 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	2.00 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

( • Carbon dioxide ) + = ( • 2)

By formula: (NO₂^- • CO₂) + CO₂ = (NO₂^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (NO₂^- • 2CO₂) + CO₂ = (NO₂^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.3 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (NO₂^- • 3CO₂) + CO₂ = (NO₂^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.9	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.7 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (NO₂^- • 4CO₂) + CO₂ = (NO₂^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (NO₂^- • 5CO₂) + CO₂ = (NO₂^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.9 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.1	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (NO₂^- • 6CO₂) + CO₂ = (NO₂^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.4 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 7 Carbon dioxide ) + = ( • 8)

By formula: (NO₂^- • 7CO₂) + CO₂ = (NO₂^- • 8CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-2.3 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

+ Carbon dioxide = ( • )

By formula: NO₃^- + CO₂ = (NO₃^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.70 ± 0.10	kcal/mol	TDAs	Banic and Iribarne, 1985	gas phase; B,M

+ Carbon dioxide = ( • )

By formula: Na⁺ + CO₂ = (Na⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15.9	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Δ_rH°	13.7	kcal/mol	FA	Perry, Rowe, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.1	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Δ_rS°	19.8	cal/mol*K	FA	Perry, Rowe, et al., 1980	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
6.6	310.	DT	Keller and Beyer, 1971	gas phase; low E/N; M

( • Carbon dioxide ) + = ( • 2)

By formula: (Na⁺ • CO₂) + CO₂ = (Na⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11.0	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.7	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
4.8	310.	DT	Keller and Beyer, 1971	gas phase; low E/N; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (Na⁺ • 2CO₂) + CO₂ = (Na⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.7	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.0	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (Na⁺ • 3CO₂) + CO₂ = (Na⁺ • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.4	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
0.7	310.	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

( • ) + Carbon dioxide = ( • • )

By formula: (Na⁺ • H₂O) + CO₂ = (Na⁺ • CO₂ • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12.6	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.5	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M

( • 2) + Carbon dioxide = ( • • 2)

By formula: (Na⁺ • 2H₂O) + CO₂ = (Na⁺ • CO₂ • 2H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.3	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.9	cal/mol*K	HPMS	Peterson, Mark, et al., 1984	gas phase; M

( • 3) + Carbon dioxide = ( • • 3)

By formula: (Na⁺ • 3H₂O) + CO₂ = (Na⁺ • CO₂ • 3H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	25.	cal/mol*K	N/A	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.3	kcal/mol	HPMS	Peterson, Mark, et al., 1984	gas phase; Entropy change calculated or estimated; M

O^- + Carbon dioxide = (O^- • )

By formula: O^- + CO₂ = (O^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	48. ± 10.	kcal/mol	AVG	N/A	Average of 8 out of 9 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	48.0 ± 5.0	kcal/mol	IMRE	Adams and Bohme, 1970	gas phase; O₃^- + CO₂ <=> CO₃^- + O₂; B

(O^- • Carbon dioxide ) + = (O^- • 2)

By formula: (O^- • CO₂) + CO₂ = (O^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.1	kcal/mol	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	21.8	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M

(O^- • ) + Carbon dioxide = (O^- • • )

By formula: (O^- • H₂O) + CO₂ = (O^- • CO₂ • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.4	kcal/mol	PDiss	Roehl, Snodgrass, et al., 1991	gas phase; Δ_rH>; M

+ Carbon dioxide = ( • )

By formula: O₂⁺ + CO₂ = (O₂⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.8 ± 0.9	kcal/mol	AVG	N/A	Average of 4 out of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	17.5	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	18.9	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=9.80 kcal/mol; M
Δ_rS°	20.7	cal/mol*K	N/A	Dotan, Davidson, et al., 1978	gas phase; switching reaction(O2+)O2, Entropy change calculated or estimated; Conway and Janik, 1970; M
Δ_rS°	20.	cal/mol*K	N/A	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	4.4	kcal/mol	DT	Rakshit and Warneck, 1981	gas phase; M
Δ_rG°	4.3	kcal/mol	FA	Dotan, Davidson, et al., 1978	gas phase; switching reaction(O2+)O2, Entropy change calculated or estimated; Conway and Janik, 1970; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
9.4	600.	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change calculated or estimated, DG>, Δ_rH>; M

( • Carbon dioxide ) + = ( • 2)

By formula: (O₂⁺ • CO₂) + CO₂ = (O₂⁺ • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.6 ± 0.5	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rH°	7.5	kcal/mol	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change is questionable; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.7	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Δ_rS°	15.	cal/mol*K	PHPMS	Meot-Ner (Mautner) and Field, 1977	gas phase; Entropy change is questionable; M

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (O₂⁺ • 2CO₂) + CO₂ = (O₂⁺ • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.2 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.8	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (O₂⁺ • 3CO₂) + CO₂ = (O₂⁺ • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.1 ± 0.3	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.6	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (O₂⁺ • 4CO₂) + CO₂ = (O₂⁺ • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.5 ± 0.5	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.0	cal/mol*K	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; M

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (O₂⁺ • 5CO₂) + CO₂ = (O₂⁺ • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.0	kcal/mol	PHPMS	Hiraoka, Nakajima, et al., 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.	cal/mol*K	N/A	Hiraoka, Nakajima, et al., 1988	gas phase; Entropy change calculated or estimated; M

+ Carbon dioxide = ( • )

By formula: O₂^- + CO₂ = (O₂^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.00 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Δ_rH°	17.7 ± 1.8	kcal/mol	IMRE	Pack and Phelps, 1966	gas phase; Corrected with more recent EA(O2) = 0.45 eV; B,M
Δ_rH°	25.4 ± 4.6	kcal/mol	PDis	Vestal and Mauclaire, 1977	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	24.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Δ_rS°	21.	cal/mol*K	DT	Pack and Phelps, 1966	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	11.7 ± 2.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B
Δ_rG°	12.2 ± 1.2	kcal/mol	IMRE	Pack and Phelps, 1966	gas phase; Corrected with more recent EA(O2) = 0.45 eV; B
Δ_rG°	10.0	kcal/mol	FA	Adams and Bohme, 1970	gas phase; switching reaction(O2-)O2; Conway and Nesbit, 1968; M

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
12.9	296.	FA	Fehsenfeld and Ferguson, 1974	gas phase; switching reaction(O2-)H2O; Arshadi and Kebarle, 1970; M

( • Carbon dioxide ) + = ( • 2)

By formula: (O₂^- • CO₂) + CO₂ = (O₂^- • 2CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.60 ± 0.20	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.2	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 2 Carbon dioxide ) + = ( • 3)

By formula: (O₂^- • 2CO₂) + CO₂ = (O₂^- • 3CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.3 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	23.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.6 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 3 Carbon dioxide ) + = ( • 4)

By formula: (O₂^- • 3CO₂) + CO₂ = (O₂^- • 4CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.7	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-0.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 4 Carbon dioxide ) + = ( • 5)

By formula: (O₂^- • 4CO₂) + CO₂ = (O₂^- • 5CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	18.4	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.1 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 5 Carbon dioxide ) + = ( • 6)

By formula: (O₂^- • 5CO₂) + CO₂ = (O₂^- • 6CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.0	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.5 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • 6 Carbon dioxide ) + = ( • 7)

By formula: (O₂^- • 6CO₂) + CO₂ = (O₂^- • 7CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.0 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	19.3	cal/mol*K	PHPMS	Hiraoka and Yamabe, 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-1.8 ± 1.0	kcal/mol	TDAs	Hiraoka and Yamabe, 1992	gas phase; B

( • ) + Carbon dioxide = ( • • )

By formula: (O₂^- • H₂O) + CO₂ = (O₂^- • CO₂ • H₂O)

Free energy of reaction

Δ_rG° (kcal/mol)	T (K)	Method	Reference	Comment
8.2	296.	FA	Fehsenfeld and Ferguson, 1974	gas phase; switching reaction(O2-)2H2O; Arshadi and Kebarle, 1970; M

O₂S⁺ + Carbon dioxide = (O₂S⁺ • )

By formula: O₂S⁺ + CO₂ = (O₂S⁺ • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.6 ± 0.2	kcal/mol	DT	Illies, 1988	gas phase; Δ_rH(0 K)=10.2 kcal/mol; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	16.5	cal/mol*K	DT	Illies, 1988	gas phase; Δ_rH(0 K)=10.2 kcal/mol; M

O₃S^- + Carbon dioxide = (O₃S^- • )

By formula: O₃S^- + CO₂ = (O₃S^- • CO₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.50 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	20.7	cal/mol*K	HPMS	Keesee, Lee, et al., 1980	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.30 ± 0.20	kcal/mol	TDAs	Keesee, Lee, et al., 1980	gas phase; B

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Gas Chromatography, References, Notes

Data compiled by: Coblentz Society, Inc.

GAS (200 mmHg DILUTED TO A TOTAL PRESSURE OF 600 mmHg WITH N2); DOW KBr FOREPRISM; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Gas Chromatography

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, References, Notes

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Kovats' RI, non-polar column, isothermal

View large format table.

Column type	Active phase	Temperature (C)	I	Reference	Comment
Packed	Squalane	27.	154.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	49.	153.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	67.	152.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	86.	152.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Gas Chromatography, Notes

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McKnight, L.G.; Sawina, J.M., Drift Velocities and Interactions of Cs+ Ions with Atmospheric Gases, J. Chem. Phys., 1972, 57, 12, 5156, https://doi.org/10.1063/1.1678205 . [all data]

Rodgers and Armentrout, 2000
Rodgers, M.T.; Armentrout, P.B., Noncovalent Metal-Ligand Bond Energies as Studied by Threshold Collision-Induced Dissociation, Mass Spectrom. Rev., 2000, 19, 4, 215, https://doi.org/10.1002/1098-2787(200007)19:4<215::AID-MAS2>3.0.CO;2-X . [all data]

Castleman and Keesee, 1981
Castleman, A.W.; Keesee, R.G., Electron and Ion Swarms, Proc. Second Int. Swarm Seminar, L. G. Christoforou, ed. (Pergamon Press, New York), 1981, 189-201. [all data]

Keller and Beyer, 1971, 2
Keller, G.E.; Beyer, R.A., Drift Tube Studies of Carbon Dioxide Clustering to Potassium and Sodium Ions, Bull. Am. Phys. Soc., 1971, 16, 214. [all data]

Praxmarer, Jordan, et al., 1993
Praxmarer, C. Hansel; Jordan, A.; Kraus, H.; Lindinger, W., Reactions of Kr2+ with Various Neutrals, Int.J. Mass Spectrom. Ion. Proc., 1993, 129, 121, https://doi.org/10.1016/0168-1176(93)87036-R . [all data]

Wadt, 1978
Wadt, W.R., The Electronic States of Ar2+, Kr2+, Xe2+. I. Potential Curves with and without Spin-Orbit Coupling, J. Chem. Phys., 1978, 68, 2, 402, https://doi.org/10.1063/1.435773 . [all data]

Radzig and Smirnov, 1985
Radzig, R.; Smirnov, B.M., Reference Data on Atoms in Molecules and Ions, Springer, Berlin, 1985. [all data]

Andersen, Muntean, et al., 2000
Andersen, A.; Muntean, F.; Walter, D.; Rue, C.; Armentrout, P.B., Collision-Induced Dissociation and Theoretical Studies of Mg+ Complexes with CO, CO2, NH3, CH4, CH3OH, and C6H6, J. Phys. Chem. A, 2000, 104, 4, 692, https://doi.org/10.1021/jp993031t . [all data]

Roehl, Snodgrass, et al., 1991
Roehl, C.M.; Snodgrass, J.T.; Deakyne, C.A.; Bowers, M.T., Photodissociation of CO3-.H2O: Observation of the O-.H2O + CO2 Product Channel, J. Chem. Phys., 1991, 94, 10, 6546, https://doi.org/10.1063/1.460281 . [all data]

Hively and Hinton, 1968
Hively, R.A.; Hinton, R.E., Variation of the retention index with temperature on squalane substrates, J. Gas Chromatogr., 1968, 6, 4, 203-217, https://doi.org/10.1093/chromsci/6.4.203 . [all data]

Notes

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Symbols used in this document:

AE	Appearance energy
EA	Electron affinity
IE (evaluated)	Recommended ionization energy
P_c	Critical pressure
P_triple	Triple point pressure
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
T_c	Critical temperature
T_triple	Triple point temperature
V_c	Critical volume
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions
Δ_subH	Enthalpy of sublimation
Δ_vapH	Enthalpy of vaporization
ρ_c	Critical density

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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