Argon

Formula: Ar
Molecular weight: 39.948
IUPAC Standard InChI: InChI=1S/Ar
IUPAC Standard InChIKey: XKRFYHLGVUSROY-UHFFFAOYSA-N
CAS Registry Number: 7440-37-1
Chemical structure:
This structure is also available as a 2d Mol file
Other names: Ar; UN 1006; UN 1951; argon atom
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Information on this page:
Other data available:
- Phase change data
- Reaction thermochemistry data: reactions 51 to 100, reactions 101 to 102
- Henry's Law data
- Fluid Properties
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Gas phase thermochemistry data

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), References, Notes

Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	154.846 ± 0.003	J/mol*K	Review	Cox, Wagman, et al., 1984	CODATA Review value
S°_{gas,1 bar}	154.84	J/mol*K	Review	Chase, 1998	Data last reviewed in March, 1982

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 (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.

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Temperature (K)	298. to 6000.
A	20.78600
B	2.825911×10^-7
C	-1.464191×10^-7
D	1.092131×10^-8
E	-3.661371×10^-8
F	-6.197350
G	179.9990
H	0.000000
Reference	Chase, 1998
Comment	Data last reviewed in March, 1982

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), References, Notes

Data compiled as indicated in comments:
RCD - Robert C. Dunbar
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

+ Argon = ( • Argon )

By formula: Li⁺ + Ar = (Li⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30. ± 4.	kJ/mol	AVG	N/A	Average of 4 out of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.	J/mol*K	DT	McKnight and Sawina, 1973	gas phase; Δ_rS approximate; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
5.9	294.	IMob	Cassidy and Elford, 1985	gas phase; M
7.9	319.	DT	Keller, Beyer, et al., 1973	gas phase; LOW E/N; M
11.	215.	DT	McKnight and Sawina, 1973	gas phase; Δ_rS approximate; M

Ar⁺ + Argon = (Ar⁺ • Argon )

By formula: Ar⁺ + Ar = (Ar⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	100. ± 90.	kJ/mol	AVG	N/A	Average of 5 out of 7 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	53.6	J/mol*K	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)Ar; Turner and Conway, 1979, Liu and Conway, 1975; M

+ Argon = ( • Argon )

By formula: K⁺ + Ar = (K⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12. ± 3.	kJ/mol	AVG	N/A	Average of 9 values; Individual data points

+ Argon = ( • Argon )

By formula: N₂⁺ + Ar = (N₂⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	112.	kJ/mol	PD/KERD	Kim and Bowers, 1990	gas phase; switching reaction(N2+)N2; Hiraoka and Nakajima, 1988; M
Δ_rH°	106.	kJ/mol	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)N2; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	81.6	J/mol*K	PD/KERD	Kim and Bowers, 1990	gas phase; switching reaction(N2+)N2; Hiraoka and Nakajima, 1988; M
Δ_rS°	57.3	J/mol*K	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)N2; M

+ Argon = ( • Argon )

By formula: Cs⁺ + Ar = (Cs⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.16	kJ/mol	IMob	Gatland, 1984	gas phase; M
Δ_rH°	6.11	kJ/mol	SCATTERING	Gislason, 1984	gas phase; M
Δ_rH°	8.20	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	9.54	kJ/mol	IMob	Takebe, 1983	gas phase; M
Δ_rH°	9.6	kJ/mol	IMob	Takebe, 1983	gas phase; values from this reference are consistently too high; M

+ Argon = ( • Argon )

By formula: Cr⁺ + Ar = (Cr⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	29. ± 2.	kJ/mol	SIDT	Kemper, Hsu, et al., 1991	gas phase; Δ_rH(0 K) = 27.4 kJ/mol, Δ_rS(100 K) = 60.2 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	66.1	J/mol*K	SIDT	Kemper, Hsu, et al., 1991	gas phase; Δ_rH(0 K) = 27.4 kJ/mol, Δ_rS(100 K) = 60.2 J/mol*K; M

+ Argon = ( • Argon )

By formula: Na⁺ + Ar = (Na⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15. ± 8.8	kJ/mol	CIDT	Armentrout and Rodgers, 2000	RCD
Δ_rH°	15.5	kJ/mol	SCATTERING	Gislason, 1984	gas phase; M
Δ_rH°	18.4	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	18.	kJ/mol	DT	McKnight and Sawina, 1973	gas phase; M
Δ_rH°	20.4	kJ/mol	IMob	Takebe, 1983	gas phase; M

H₃⁺ + Argon = (H₃⁺ • Argon )

By formula: H₃⁺ + Ar = (H₃⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	28.0 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Δ_rH°	31. ± 3.	kJ/mol	SIFT	Bedford and Smith, 1990	gas phase; switching reaction(H3+)H2, Hiraoka and Mori, 1989; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	56.1	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

Xe⁺ + Argon = (Xe⁺ • Argon )

By formula: Xe⁺ + Ar = (Xe⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.	kJ/mol	PI	Dehmer and Pratt, 1982	gas phase; M
Δ_rH°	25.	kJ/mol	SIFT	Jones, Lister, et al., 1980	gas phase; M
Δ_rH°	13.	kJ/mol	PI	Ng, Tiedemann, et al., 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	81.2	J/mol*K	SIFT	Jones, Lister, et al., 1980	gas phase; M

(Ar⁺ • 2 Argon ) + Argon = (Ar⁺ • 3 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
8.4	77.	PHPMS	Teng and Conway, 1973	gas phase; M

( • 7 Argon ) + Argon = ( • 8 Argon )

By formula: (N₂⁺ • 7Ar) + Ar = (N₂⁺ • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.40	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	N/A	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M

( • 8 Argon ) + Argon = ( • 9 Argon )

By formula: (N₂⁺ • 8Ar) + Ar = (N₂⁺ • 9Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.36	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	N/A	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M

+ Argon = ArF^-

By formula: F^- + Ar = ArF^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.37	kJ/mol	TDAs	Wada, Kikkawa, et al., 2007	gas phase; Entropy estimated; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-16.6	kJ/mol	TDAs	Wada, Kikkawa, et al., 2007	gas phase; Entropy estimated; B

+ Argon = ( • Argon )

By formula: Rb⁺ + Ar = (Rb⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.49	kJ/mol	IMob	Gatland, 1984	gas phase; M
Δ_rH°	8.28	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	11.9	kJ/mol	IMob	Takebe, 1983	gas phase; M

(O^- • 10 Argon ) + Argon = (O^- • 11 Argon )

By formula: (O^- • 10Ar) + Ar = (O^- • 11Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 11 Argon ) + Argon = (O^- • 12 Argon )

By formula: (O^- • 11Ar) + Ar = (O^- • 12Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 12 Argon ) + Argon = (O^- • 13 Argon )

By formula: (O^- • 12Ar) + Ar = (O^- • 13Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 13 Argon ) + Argon = (O^- • 14 Argon )

By formula: (O^- • 13Ar) + Ar = (O^- • 14Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 14 Argon ) + Argon = (O^- • 15 Argon )

By formula: (O^- • 14Ar) + Ar = (O^- • 15Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 15 Argon ) + Argon = (O^- • 16 Argon )

By formula: (O^- • 15Ar) + Ar = (O^- • 16Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 16 Argon ) + Argon = (O^- • 17 Argon )

By formula: (O^- • 16Ar) + Ar = (O^- • 17Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 17 Argon ) + Argon = (O^- • 18 Argon )

By formula: (O^- • 17Ar) + Ar = (O^- • 18Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 18 Argon ) + Argon = (O^- • 19 Argon )

By formula: (O^- • 18Ar) + Ar = (O^- • 19Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 19 Argon ) + Argon = (O^- • 20 Argon )

By formula: (O^- • 19Ar) + Ar = (O^- • 20Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 20 Argon ) + Argon = (O^- • 21 Argon )

By formula: (O^- • 20Ar) + Ar = (O^- • 21Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 21 Argon ) + Argon = (O^- • 22 Argon )

By formula: (O^- • 21Ar) + Ar = (O^- • 22Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 22 Argon ) + Argon = (O^- • 23 Argon )

By formula: (O^- • 22Ar) + Ar = (O^- • 23Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 23 Argon ) + Argon = (O^- • 24 Argon )

By formula: (O^- • 23Ar) + Ar = (O^- • 24Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 24 Argon ) + Argon = (O^- • 25 Argon )

By formula: (O^- • 24Ar) + Ar = (O^- • 25Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 25 Argon ) + Argon = (O^- • 26 Argon )

By formula: (O^- • 25Ar) + Ar = (O^- • 26Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 9 Argon ) + Argon = (O^- • 10 Argon )

By formula: (O^- • 9Ar) + Ar = (O^- • 10Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 2 Argon ) + Argon = (O^- • 3 Argon )

By formula: (O^- • 2Ar) + Ar = (O^- • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.7 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 3 Argon ) + Argon = (O^- • 4 Argon )

By formula: (O^- • 3Ar) + Ar = (O^- • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.9 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 4 Argon ) + Argon = (O^- • 5 Argon )

By formula: (O^- • 4Ar) + Ar = (O^- • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.0 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 5 Argon ) + Argon = (O^- • 6 Argon )

By formula: (O^- • 5Ar) + Ar = (O^- • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.0 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 6 Argon ) + Argon = (O^- • 7 Argon )

By formula: (O^- • 6Ar) + Ar = (O^- • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 7 Argon ) + Argon = (O^- • 8 Argon )

By formula: (O^- • 7Ar) + Ar = (O^- • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 8 Argon ) + Argon = (O^- • 9 Argon )

By formula: (O^- • 8Ar) + Ar = (O^- • 9Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • Argon ) + Argon = (O^- • 2 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(Ar⁺ • Argon ) + Argon = (Ar⁺ • 2 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.2 ± 0.3	kJ/mol	PHPMS	Turner and Conway, 1979	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.9	J/mol*K	PHPMS	Turner and Conway, 1979	gas phase; M

( • Argon ) + Argon = ( • 2 Argon )

By formula: (N₂⁺ • Ar) + Ar = (N₂⁺ • 2Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Δ_rH>; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Δ_rH>; M

O^- + Argon = (O^- • Argon )

By formula: O^- + Ar = (O^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.2 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(Ar⁺ • 10 Argon ) + Argon = (Ar⁺ • 11 Argon )

By formula: (Ar⁺ • 10Ar) + Ar = (Ar⁺ • 11Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 9 Argon ) + Argon = (Ar⁺ • 10 Argon )

By formula: (Ar⁺ • 9Ar) + Ar = (Ar⁺ • 10Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.49 ± 0.84	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.5	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(D₃⁺ • 2 Argon ) + Argon = (D₃⁺ • 3 Argon )

By formula: (D₃⁺ • 2Ar) + Ar = (D₃⁺ • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.6 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	77.0	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 3 Argon ) + Argon = (D₃⁺ • 4 Argon )

By formula: (D₃⁺ • 3Ar) + Ar = (D₃⁺ • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.2 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	69.5	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 4 Argon ) + Argon = (D₃⁺ • 5 Argon )

By formula: (D₃⁺ • 4Ar) + Ar = (D₃⁺ • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 5 Argon ) + Argon = (D₃⁺ • 6 Argon )

By formula: (D₃⁺ • 5Ar) + Ar = (D₃⁺ • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.1 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	79.9	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 6 Argon ) + Argon = (D₃⁺ • 7 Argon )

By formula: (D₃⁺ • 6Ar) + Ar = (D₃⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	105.	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(Ar⁺ • 3 Argon ) + Argon = (Ar⁺ • 4 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.0 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	58.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Ion clustering data, Mass spectrum (electron ionization), 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
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	15.759 ± 0.001	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	369.2	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	346.3	kJ/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
15.763	PIPECO	Weitzel, Mahnert, et al., 1994	LL
15.75962	EVAL	Lide, 1992	LL
15.82	EI	Wetzel, Baiocchi, et al., 1987	LBLHLM
15.760	S	Kelly, 1987	LBLHLM
15.759	PE	Kimura, Katsumata, et al., 1981	LLK
15.88	EI	Clare and Sowerby, 1981	LLK
15.7	EI	Freiser, 1980	LLK
15.75962 ± 0.00001	S	Minnhagen, 1973	LLK
15.753 ± 0.002	TE	Spohr, Guyon, et al., 1971	LLK
15.75962 ± 0.00001	S	Yoshino, 1970	RDSH
15.759	S	Yoshino, 1969	RDSH
15.713 ± 0.003	CI	Hotop and Niehaus, 1969	RDSH
15.757 ± 0.005	PE	Collin and Natalis, 1968	RDSH
15.74 ± 0.05	EI	Gallegos and Klaver, 1967	RDSH
15.78 ± 0.03	EI	Winters, Collins, et al., 1966	RDSH
15.79	PE	Al-Joboury and Turner, 1963	RDSH

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

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

Ar⁺ + Argon = (Ar⁺ • Argon )

By formula: Ar⁺ + Ar = (Ar⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	100. ± 90.	kJ/mol	AVG	N/A	Average of 5 out of 7 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	53.6	J/mol*K	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)Ar; Turner and Conway, 1979, Liu and Conway, 1975; M

(Ar⁺ • Argon ) + Argon = (Ar⁺ • 2 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.2 ± 0.3	kJ/mol	PHPMS	Turner and Conway, 1979	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.9	J/mol*K	PHPMS	Turner and Conway, 1979	gas phase; M

(Ar⁺ • 2 Argon ) + Argon = (Ar⁺ • 3 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
8.4	77.	PHPMS	Teng and Conway, 1973	gas phase; M

(Ar⁺ • 3 Argon ) + Argon = (Ar⁺ • 4 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.0 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	58.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 4 Argon ) + Argon = (Ar⁺ • 5 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.8 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	67.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 5 Argon ) + Argon = (Ar⁺ • 6 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.8 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.1	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 6 Argon ) + Argon = (Ar⁺ • 7 Argon )

By formula: (Ar⁺ • 6Ar) + Ar = (Ar⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.7 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 7 Argon ) + Argon = (Ar⁺ • 8 Argon )

By formula: (Ar⁺ • 7Ar) + Ar = (Ar⁺ • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.7 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 8 Argon ) + Argon = (Ar⁺ • 9 Argon )

By formula: (Ar⁺ • 8Ar) + Ar = (Ar⁺ • 9Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.6 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 9 Argon ) + Argon = (Ar⁺ • 10 Argon )

By formula: (Ar⁺ • 9Ar) + Ar = (Ar⁺ • 10Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.49 ± 0.84	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.5	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

(Ar⁺ • 10 Argon ) + Argon = (Ar⁺ • 11 Argon )

By formula: (Ar⁺ • 10Ar) + Ar = (Ar⁺ • 11Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989, 2	gas phase; M

ArNO^- + 2 Argon = Ar₂NO^-

By formula: ArNO^- + 2Ar = Ar₂NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.28	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₂NO^- + 3 Argon = Ar₃NO^-

By formula: Ar₂NO^- + 3Ar = Ar₃NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.44	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₃NO^- + 4 Argon = Ar₄NO^-

By formula: Ar₃NO^- + 4Ar = Ar₄NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.44	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₄NO^- + 5 Argon = Ar₅NO^-

By formula: Ar₄NO^- + 5Ar = Ar₅NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.44	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₅NO^- + 6 Argon = Ar₆NO^-

By formula: Ar₅NO^- + 6Ar = Ar₆NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.02	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₆NO^- + 7 Argon = Ar₇NO^-

By formula: Ar₆NO^- + 7Ar = Ar₇NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.8	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₇NO^- + 8 Argon = Ar₈NO^-

By formula: Ar₇NO^- + 8Ar = Ar₈NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.8	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₈NO^- + 9 Argon = Ar₉NO^-

By formula: Ar₈NO^- + 9Ar = Ar₉NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.9	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₉NO^- + 10 Argon = Ar₁₀NO^-

By formula: Ar₉NO^- + 10Ar = Ar₁₀NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.9	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₁₀NO^- + 11 Argon = Ar₁₁NO^-

By formula: Ar₁₀NO^- + 11Ar = Ar₁₁NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.5	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₁₁NO^- + 12 Argon = Ar₁₂NO^-

By formula: Ar₁₁NO^- + 12Ar = Ar₁₂NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.9	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₁₂NO^- + 13 Argon = Ar₁₃NO^-

By formula: Ar₁₂NO^- + 13Ar = Ar₁₃NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1.3	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

Ar₁₃NO^- + 14 Argon = Ar₁₄NO^-

By formula: Ar₁₃NO^- + 14Ar = Ar₁₄NO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.84	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B

+ Argon = ( • Argon )

By formula: Br^- + Ar = (Br^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.3	kJ/mol	Ther	Zhao, Yourshaw, et al., 1994	gas phase; B
Δ_rH°	5.86	kJ/mol	Mobl	Gatland, 1984, 2	gas phase; B,M

+ Argon = ( • Argon )

By formula: CH₃⁺ + Ar = (CH₃⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	47.3 ± 8.4	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.1	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • Argon ) + Argon = ( • 2 Argon )

By formula: (CH₃⁺ • Ar) + Ar = (CH₃⁺ • 2Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.5 ± 0.8	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	65.7	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 2 Argon ) + Argon = ( • 3 Argon )

By formula: (CH₃⁺ • 2Ar) + Ar = (CH₃⁺ • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.2 ± 0.8	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	93.3	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 3 Argon ) + Argon = ( • 4 Argon )

By formula: (CH₃⁺ • 3Ar) + Ar = (CH₃⁺ • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.2 ± 0.8	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	88.3	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 4 Argon ) + Argon = ( • 5 Argon )

By formula: (CH₃⁺ • 4Ar) + Ar = (CH₃⁺ • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.1 ± 0.8	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	86.2	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 5 Argon ) + Argon = ( • 6 Argon )

By formula: (CH₃⁺ • 5Ar) + Ar = (CH₃⁺ • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8. ± 1.	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	87.9	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 6 Argon ) + Argon = ( • 7 Argon )

By formula: (CH₃⁺ • 6Ar) + Ar = (CH₃⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8. ± 2.	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	88.7	J/mol*K	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; M

( • 7 Argon ) + Argon = ( • 8 Argon )

By formula: (CH₃⁺ • 7Ar) + Ar = (CH₃⁺ • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.08	kJ/mol	PHPMS	Hiraoka, Kudaka, et al., 1991	gas phase; Entropy change calculated or estimated; M

CO⁺ + Argon = (CO⁺ • Argon )

By formula: CO⁺ + Ar = (CO⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	67.4 ± 5.9	kJ/mol	PIPECO	Norwood, Guo, et al., 1989	gas phase; CO+(X) ground state; M

+ Argon = ( • Argon )

By formula: CO₂⁺ + Ar = (CO₂⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	25.	kJ/mol	PI	Pratt and Dehmer, 1983	gas phase; M

+ Argon = ( • Argon )

By formula: Co⁺ + Ar = (Co⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	49.4	kJ/mol	PDis	Asher, Bellert, et al., 1994	RCD

+ Argon = ( • Argon )

By formula: Cr⁺ + Ar = (Cr⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	29. ± 2.	kJ/mol	SIDT	Kemper, Hsu, et al., 1991	gas phase; Δ_rH(0 K) = 27.4 kJ/mol, Δ_rS(100 K) = 60.2 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	66.1	J/mol*K	SIDT	Kemper, Hsu, et al., 1991	gas phase; Δ_rH(0 K) = 27.4 kJ/mol, Δ_rS(100 K) = 60.2 J/mol*K; M

+ Argon = ( • Argon )

By formula: Cs⁺ + Ar = (Cs⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.16	kJ/mol	IMob	Gatland, 1984	gas phase; M
Δ_rH°	6.11	kJ/mol	SCATTERING	Gislason, 1984	gas phase; M
Δ_rH°	8.20	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	9.54	kJ/mol	IMob	Takebe, 1983	gas phase; M
Δ_rH°	9.6	kJ/mol	IMob	Takebe, 1983	gas phase; values from this reference are consistently too high; M

D₃⁺ + Argon = (D₃⁺ • Argon )

By formula: D₃⁺ + Ar = (D₃⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	29.1 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	60.7	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • Argon ) + Argon = (D₃⁺ • 2 Argon )

By formula: (D₃⁺ • Ar) + Ar = (D₃⁺ • 2Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20.1 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	73.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 2 Argon ) + Argon = (D₃⁺ • 3 Argon )

By formula: (D₃⁺ • 2Ar) + Ar = (D₃⁺ • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.6 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	77.0	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 3 Argon ) + Argon = (D₃⁺ • 4 Argon )

By formula: (D₃⁺ • 3Ar) + Ar = (D₃⁺ • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.2 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	69.5	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 4 Argon ) + Argon = (D₃⁺ • 5 Argon )

By formula: (D₃⁺ • 4Ar) + Ar = (D₃⁺ • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 5 Argon ) + Argon = (D₃⁺ • 6 Argon )

By formula: (D₃⁺ • 5Ar) + Ar = (D₃⁺ • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.1 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	79.9	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(D₃⁺ • 6 Argon ) + Argon = (D₃⁺ • 7 Argon )

By formula: (D₃⁺ • 6Ar) + Ar = (D₃⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	105.	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

+ Argon = ArF^-

By formula: F^- + Ar = ArF^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.37	kJ/mol	TDAs	Wada, Kikkawa, et al., 2007	gas phase; Entropy estimated; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	-16.6	kJ/mol	TDAs	Wada, Kikkawa, et al., 2007	gas phase; Entropy estimated; B

+ Argon = ( • Argon )

By formula: Fe⁺ + Ar = (Fe⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	11. ± 7.9	kJ/mol	CIDT	Rodgers and Armentrout, 2000	RCD

+ Argon = ( • Argon )

By formula: H₂⁺ + Ar = (H₂⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	100.	kJ/mol	SIFT	Bedford and Smith, 1990	gas phase; switching reaction(Ar+)Ar, Δ_rH>; M

H₃⁺ + Argon = (H₃⁺ • Argon )

By formula: H₃⁺ + Ar = (H₃⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	28.0 ± 0.8	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Δ_rH°	31. ± 3.	kJ/mol	SIFT	Bedford and Smith, 1990	gas phase; switching reaction(H3+)H2, Hiraoka and Mori, 1989; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	56.1	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • Argon ) + Argon = (H₃⁺ • 2 Argon )

By formula: (H₃⁺ • Ar) + Ar = (H₃⁺ • 2Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.1 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	66.9	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • 2 Argon ) + Argon = (H₃⁺ • 3 Argon )

By formula: (H₃⁺ • 2Ar) + Ar = (H₃⁺ • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.9 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • 3 Argon ) + Argon = (H₃⁺ • 4 Argon )

By formula: (H₃⁺ • 3Ar) + Ar = (H₃⁺ • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.3 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	67.4	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • 4 Argon ) + Argon = (H₃⁺ • 5 Argon )

By formula: (H₃⁺ • 4Ar) + Ar = (H₃⁺ • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	69.9	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • 5 Argon ) + Argon = (H₃⁺ • 6 Argon )

By formula: (H₃⁺ • 5Ar) + Ar = (H₃⁺ • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.1 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	78.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(H₃⁺ • 6 Argon ) + Argon = (H₃⁺ • 7 Argon )

By formula: (H₃⁺ • 6Ar) + Ar = (H₃⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.4	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

Hg⁺ + Argon = (Hg⁺ • Argon )

By formula: Hg⁺ + Ar = (Hg⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22. ± 2.	kJ/mol	PI	Linn, Brom, et al., 1985	gas phase; M

+ Argon = ( • Argon )

By formula: I^- + Ar = (I^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2.5	kJ/mol	Ther	Zhao, Yourshaw, et al., 1994	gas phase; B

+ Argon = ( • Argon )

By formula: K⁺ + Ar = (K⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	12. ± 3.	kJ/mol	AVG	N/A	Average of 9 values; Individual data points

Kr⁺ + Argon = (Kr⁺ • Argon )

By formula: Kr⁺ + Ar = (Kr⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.0	kJ/mol	PI	Dehmer and Pratt, 1982	gas phase; M
Δ_rH°	56.9	kJ/mol	PI	Ng, Tiedemann, et al., 1977	gas phase; M

+ Argon = ( • Argon )

By formula: Li⁺ + Ar = (Li⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	30. ± 4.	kJ/mol	AVG	N/A	Average of 4 out of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.	J/mol*K	DT	McKnight and Sawina, 1973	gas phase; Δ_rS approximate; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
5.9	294.	IMob	Cassidy and Elford, 1985	gas phase; M
7.9	319.	DT	Keller, Beyer, et al., 1973	gas phase; LOW E/N; M
11.	215.	DT	McKnight and Sawina, 1973	gas phase; Δ_rS approximate; M

+ Argon = ( • Argon )

By formula: Mg⁺ + Ar = (Mg⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.6 ± 6.7	kJ/mol	CIDT	Andersen, Muntean, et al., 2000	RCD

N⁺ + Argon = (N⁺ • Argon )

By formula: N⁺ + Ar = (N⁺ • Ar)

Enthalpy of reaction

Δ_rH° (kJ/mol)	T (K)	Method	Reference	Comment
118. (+44.,-0.)		CID	Haynes, Freysinger, et al., 1995	gas phase; giuded ion beam CID; M

+ Argon = ( • Argon )

By formula: NO^- + Ar = (NO^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.4 ± 3.8	kJ/mol	N/A	Hendricks, de Clercq, et al., 2002	gas phase; B
Δ_rH°	6.7 ± 1.3	kJ/mol	N/A	Bowen and Eaton, 1988	gas phase; B

+ Argon = ( • Argon )

By formula: N₂⁺ + Ar = (N₂⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	112.	kJ/mol	PD/KERD	Kim and Bowers, 1990	gas phase; switching reaction(N2+)N2; Hiraoka and Nakajima, 1988; M
Δ_rH°	106.	kJ/mol	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)N2; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	81.6	J/mol*K	PD/KERD	Kim and Bowers, 1990	gas phase; switching reaction(N2+)N2; Hiraoka and Nakajima, 1988; M
Δ_rS°	57.3	J/mol*K	PHPMS	Teng and Conway, 1973	gas phase; switching reaction(N2+)N2; M

( • Argon ) + Argon = ( • 2 Argon )

By formula: (N₂⁺ • Ar) + Ar = (N₂⁺ • 2Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	16.	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Δ_rH>; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Δ_rH>; M

( • 2 Argon ) + Argon = ( • 3 Argon )

By formula: (N₂⁺ • 2Ar) + Ar = (N₂⁺ • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.3 ± 0.8	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	57.3	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M

( • 3 Argon ) + Argon = ( • 4 Argon )

By formula: (N₂⁺ • 3Ar) + Ar = (N₂⁺ • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	74.9	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M

( • 4 Argon ) + Argon = ( • 5 Argon )

By formula: (N₂⁺ • 4Ar) + Ar = (N₂⁺ • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.6 ± 0.8	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.1	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M

( • 5 Argon ) + Argon = ( • 6 Argon )

By formula: (N₂⁺ • 5Ar) + Ar = (N₂⁺ • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.5 ± 0.8	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M

( • 6 Argon ) + Argon = ( • 7 Argon )

By formula: (N₂⁺ • 6Ar) + Ar = (N₂⁺ • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.4 ± 0.8	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.4	J/mol*K	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; M

( • 7 Argon ) + Argon = ( • 8 Argon )

By formula: (N₂⁺ • 7Ar) + Ar = (N₂⁺ • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.40	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	N/A	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M

( • 8 Argon ) + Argon = ( • 9 Argon )

By formula: (N₂⁺ • 8Ar) + Ar = (N₂⁺ • 9Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.36	kJ/mol	PHPMS	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	71.	J/mol*K	N/A	Hiraoka, Mori, et al., 1992	gas phase; Entropy change calculated or estimated; M

+ Argon = ( • Argon )

By formula: Na⁺ + Ar = (Na⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	15. ± 8.8	kJ/mol	CIDT	Armentrout and Rodgers, 2000	RCD
Δ_rH°	15.5	kJ/mol	SCATTERING	Gislason, 1984	gas phase; M
Δ_rH°	18.4	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	18.	kJ/mol	DT	McKnight and Sawina, 1973	gas phase; M
Δ_rH°	20.4	kJ/mol	IMob	Takebe, 1983	gas phase; M

O^- + Argon = (O^- • Argon )

By formula: O^- + Ar = (O^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.2 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • Argon ) + Argon = (O^- • 2 Argon )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 2 Argon ) + Argon = (O^- • 3 Argon )

By formula: (O^- • 2Ar) + Ar = (O^- • 3Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.7 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 3 Argon ) + Argon = (O^- • 4 Argon )

By formula: (O^- • 3Ar) + Ar = (O^- • 4Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.9 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 4 Argon ) + Argon = (O^- • 5 Argon )

By formula: (O^- • 4Ar) + Ar = (O^- • 5Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.0 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 5 Argon ) + Argon = (O^- • 6 Argon )

By formula: (O^- • 5Ar) + Ar = (O^- • 6Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	5.0 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 6 Argon ) + Argon = (O^- • 7 Argon )

By formula: (O^- • 6Ar) + Ar = (O^- • 7Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4.2 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 7 Argon ) + Argon = (O^- • 8 Argon )

By formula: (O^- • 7Ar) + Ar = (O^- • 8Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 8 Argon ) + Argon = (O^- • 9 Argon )

By formula: (O^- • 8Ar) + Ar = (O^- • 9Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	4. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 9 Argon ) + Argon = (O^- • 10 Argon )

By formula: (O^- • 9Ar) + Ar = (O^- • 10Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 10 Argon ) + Argon = (O^- • 11 Argon )

By formula: (O^- • 10Ar) + Ar = (O^- • 11Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 11 Argon ) + Argon = (O^- • 12 Argon )

By formula: (O^- • 11Ar) + Ar = (O^- • 12Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 12 Argon ) + Argon = (O^- • 13 Argon )

By formula: (O^- • 12Ar) + Ar = (O^- • 13Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 13 Argon ) + Argon = (O^- • 14 Argon )

By formula: (O^- • 13Ar) + Ar = (O^- • 14Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 14 Argon ) + Argon = (O^- • 15 Argon )

By formula: (O^- • 14Ar) + Ar = (O^- • 15Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	2. ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 15 Argon ) + Argon = (O^- • 16 Argon )

By formula: (O^- • 15Ar) + Ar = (O^- • 16Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 16 Argon ) + Argon = (O^- • 17 Argon )

By formula: (O^- • 16Ar) + Ar = (O^- • 17Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 17 Argon ) + Argon = (O^- • 18 Argon )

By formula: (O^- • 17Ar) + Ar = (O^- • 18Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 18 Argon ) + Argon = (O^- • 19 Argon )

By formula: (O^- • 18Ar) + Ar = (O^- • 19Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 19 Argon ) + Argon = (O^- • 20 Argon )

By formula: (O^- • 19Ar) + Ar = (O^- • 20Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 20 Argon ) + Argon = (O^- • 21 Argon )

By formula: (O^- • 20Ar) + Ar = (O^- • 21Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 21 Argon ) + Argon = (O^- • 22 Argon )

By formula: (O^- • 21Ar) + Ar = (O^- • 22Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 22 Argon ) + Argon = (O^- • 23 Argon )

By formula: (O^- • 22Ar) + Ar = (O^- • 23Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 23 Argon ) + Argon = (O^- • 24 Argon )

By formula: (O^- • 23Ar) + Ar = (O^- • 24Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.4 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 24 Argon ) + Argon = (O^- • 25 Argon )

By formula: (O^- • 24Ar) + Ar = (O^- • 25Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

(O^- • 25 Argon ) + Argon = (O^- • 26 Argon )

By formula: (O^- • 25Ar) + Ar = (O^- • 26Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	0.8 ± 8.4	kJ/mol	N/A	Arnold, Hendricks, et al., 1995	gas phase; EA given is Vertical Detachment Energy. Affinity: difference between successive EAs in (Y); B

+ Argon = ( • Argon )

By formula: O₂^- + Ar = (O₂^- • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6.95	kJ/mol	N/A	Bowen and Eaton, 1988	gas phase; Bound by 70 meV relative to EA(O2-.); B

+ Argon = ( • Argon )

By formula: Rb⁺ + Ar = (Rb⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	8.49	kJ/mol	IMob	Gatland, 1984	gas phase; M
Δ_rH°	8.28	kJ/mol	IMob	Viehland, 1984	gas phase; M
Δ_rH°	11.9	kJ/mol	IMob	Takebe, 1983	gas phase; M

Xe⁺ + Argon = (Xe⁺ • Argon )

By formula: Xe⁺ + Ar = (Xe⁺ • Ar)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	17.	kJ/mol	PI	Dehmer and Pratt, 1982	gas phase; M
Δ_rH°	25.	kJ/mol	SIFT	Jones, Lister, et al., 1980	gas phase; M
Δ_rH°	13.	kJ/mol	PI	Ng, Tiedemann, et al., 1977	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	81.2	J/mol*K	SIFT	Jones, Lister, et al., 1980	gas phase; M

Mass spectrum (electron ionization)

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

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

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Origin	DOW CHEMICAL COMPANY / ASTM E14-UNCERTIFIED SPECTRUM 1
NIST MS number	34321

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References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Notes

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

McKnight and Sawina, 1973
McKnight, L.G.; Sawina, J.M., Equilibrium Constants and Binding Energies of Alkali Metal Ions with Inert Gases, Bull. Am. Phys. Soc., 1973, 18, 804. [all data]

Cassidy and Elford, 1985
Cassidy, R.A.; Elford, M.T., The Mobility of Li+ Ions in Helium and Argon, Aust. J. Phys., 1985, 38, 4, 587, https://doi.org/10.1071/PH850587 . [all data]

Keller, Beyer, et al., 1973
Keller, C.E.; Beyer, R.A.; Colonna-Romano, L.M., Clustering of Ar to Li+ and a Comparison of Drift - Tube Models, Phys. Rev. A, 1973, 8, 3, 1446, https://doi.org/10.1103/PhysRevA.8.1446 . [all data]

Teng and Conway, 1973
Teng, H.H.; Conway, D.C., Ion - Molecule Equilibria in Mixtures of N2 and Ar, J. Chem. Phys., 1973, 59, 5, 2316, https://doi.org/10.1063/1.1680338 . [all data]

Turner and Conway, 1979
Turner, D.L.; Conway, D.C., Study of the 2Ar + Ar2+ = Ar + Ar3+ Reaction, J. Chem. Phys., 1979, 71, 4, 1899, https://doi.org/10.1063/1.438544 . [all data]

Liu and Conway, 1975
Liu, W.F.; Conway, D.C., Ion - Molecule Reactions in Ar at 296, 195, and 77 K, J. Chem. Phys., 1975, 62, 8, 3070, https://doi.org/10.1063/1.430906 . [all data]

Kim and Bowers, 1990
Kim, H.S.; Bowers, M.T., Energetics, Structure and Photodissociation Dynamics of the Cluster Ar.N2+, J. Chem. Phys., 1990, 93, 2, 1158, https://doi.org/10.1063/1.459179 . [all data]

Hiraoka and Nakajima, 1988
Hiraoka, K.; Nakajima, G., A Determination of the Stabilities of N2+(N2)n and O2+(N2)n with n = 1 - 11 from Measurements of the Gas - Phase Ion Equilibria, J. Chem. Phys., 1988, 88, 12, 7709, https://doi.org/10.1063/1.454285 . [all data]

Gatland, 1984
Gatland, I.R., Swarms of Ions and Electrons in Gases, W. Lindinger, T. D. Mark and F. Howorka, eds. (Springer, New York, 1984, 1984, 44. [all data]

Gislason, 1984
Gislason, E.A., Quoted in I. R. Gatland in Swarms of Ions and Electrons in Gases, W. Lindinger, T. D. Mark and F. Howorka, eds. (Springer, New York, 1984, 1984, 44. [all data]

Viehland, 1984
Viehland, L.A., Interaction Potentials for Li+ - Rare - Gas Systems, Chem. Phys., 1984, 78, 2, 279, https://doi.org/10.1016/0301-0104(83)85114-3 . [all data]

Takebe, 1983
Takebe, M., The Generalized Mobility Curve for Alkali Ions in Rare Gases: Clustering Reactions and Mobility Curves, J. Chem. Phys., 1983, 78, 12, 7223, https://doi.org/10.1063/1.444763 . [all data]

Kemper, Hsu, et al., 1991
Kemper, P.R.; Hsu, M.T.; Bowers, M.T., Transition - Metal Ion - Rare Gas Clusters: Bond Strengths and Molecular Parameters for Co+(He/Ne)n, Ni+(He/Ne)n, and Cr+(He/Ne/Ar), J. Phys. Chem., 1991, 95, 26, 10600, https://doi.org/10.1021/j100179a022 . [all data]

Armentrout and Rodgers, 2000
Armentrout, P.B.; Rodgers, M.T., An Absolute Sodium Cation Affinity Scale: Threshold Collision-Induced Dissociation Experiments and ab Initio Theory, J. Phys. Chem A, 2000, 104, 11, 2238, https://doi.org/10.1021/jp991716n . [all data]

Hiraoka and Mori, 1989
Hiraoka, K.; Mori, T., Isotope Effect and Nature of Bonding in the Cluster Ions H3+(Ar)n and D3+(Ar)n, J. Chem. Phys., 1989, 91, 8, 4821, https://doi.org/10.1063/1.456720 . [all data]

Bedford and Smith, 1990
Bedford, D.K.; Smith, D., Variable-temperature selected ion flow tube studies of the reactions of Ar+, Ar2+ and ArHn+ (n=1-3) ions with H2, HD and D2 at 300 K and 80 K, Int. J. Mass Spectrom. Ion Proc., 1990, 98, 2, 179, https://doi.org/10.1016/0168-1176(90)85017-V . [all data]

Dehmer and Pratt, 1982
Dehmer, P.M.; Pratt, S.T., Photoionization of ArKr, ArXe, and KrXe and bond dissociation energies of the rare gas dimer ions, J. Chem. Phys., 1982, 77, 4804. [all data]

Jones, Lister, et al., 1980
Jones, J.D.C.; Lister, D.G.; Twiddy, N.D., Equilibrium Constant for the Reaction Xe+ + 2Ar ---> XeAr+ + Ar in the Temperature Range 150 - 300 K and the Dissociation Energy of XeAr+, Chem. Phys. Lett., 1980, 70, 3, 575, https://doi.org/10.1016/0009-2614(80)80128-X . [all data]

Ng, Tiedemann, et al., 1977
Ng, C.Y.; Tiedemann, P.W.; Mahan, B.H.; Lee, Y.T., Photoionization Studies of the Diatomic Internuclear Rare Gas Molecules XeKr, XeAr, and KrAr, J. Chem. Phys., 1977, 66, 12, 5737, https://doi.org/10.1063/1.433848 . [all data]

Hiraoka and Mori, 1989, 2
Hiraoka, K.; Mori, T., Formation and Stabilities of Cluster Ions Arn+, J. Chem. Phys., 1989, 90, 12, 7143, https://doi.org/10.1063/1.456245 . [all data]

Hiraoka, Mori, et al., 1992
Hiraoka, K.; Mori, T.; Yamabe, S., Gas-Phase Solvation of N2+ with Ar Atoms - A Charge Switch in the Reaction N2+(Ar)...Ar+(N2), Chem. Phys. Lett., 1992, 189, 1, 7, https://doi.org/10.1016/0009-2614(92)85144-Y . [all data]

Wada, Kikkawa, et al., 2007
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Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), References

Symbols used in this document:

IE (evaluated)	Recommended ionization energy
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
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

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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NIST Chemistry WebBook, SRD 69

Argon

Data at NIST subscription sites:

Gas phase thermochemistry data

Gas Phase Heat Capacity (Shomate Equation)

Reaction thermochemistry data

Reactions 1 to 50

Free energy of reaction

Free energy of reaction

Gas phase ion energetics data

Ionization energy determinations

Ion clustering data

Clustering reactions

Free energy of reaction

Free energy of reaction

Enthalpy of reaction

Mass spectrum (electron ionization)

Spectrum

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