Hydrogen cyanide

Formula: CHN
Molecular weight: 27.0253
IUPAC Standard InChI: InChI=1S/CHN/c1-2/h1H
IUPAC Standard InChIKey: LELOWRISYMNNSU-UHFFFAOYSA-N
CAS Registry Number: 74-90-8
Chemical structure:
This structure is also available as a 2d Mol file
Other names: Hydrocyanic acid; AC; Blausaeure (German); Carbon hydride nitride (CHN); Formic anammonide; Formonitrile; HCN; Prussic Acid; Cyclon; Acide cyanhydrique; Acido cianidrico; Aero Liquid HCN; Blausaeure; Blauwzuur; Cyaanwaterstof; Cyanwasserstoff; Cyclone B; Cyjanowodor; Evercyn; NA 1051; Prussic acid, unstabilized; Rcra waste number P063; UN 1051; Zaclondiscoids; Carbon hydride nitride; Zootic acid; Agent AC; Nitrilomethane
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- Condensed phase thermochemistry data
- Phase change data
- Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 92
- Henry's Law data
- Gas phase ion energetics data
- IR Spectrum
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- Gas Chromatography
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Ion clustering data

Go To: Top, Mass spectrum (electron ionization), References, Notes

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

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

+ Hydrogen cyanide = ( • )

By formula: Br^- + CHN = (Br^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	81.2 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Δ_rH°	66.9 ± 8.4	kJ/mol	Est	Larson and McMahon, 1984	gas phase; Extrapolated from other halide data; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	82.8	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	56.5 ± 6.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • Hydrogen cyanide ) + = ( • 2)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	68.2 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.0	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	39.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 2 Hydrogen cyanide ) + = ( • 3)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	53.6 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	91.6	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	26.4	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 3 Hydrogen cyanide ) + = ( • 4)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	43.5 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.5	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.9	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 4 Hydrogen cyanide ) + = ( • 5)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	34. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	77.4	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.9	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

+ Hydrogen cyanide = ( • )

By formula: CHO₂^- + CHN = (CHO₂^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	92.0	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.	J/mol*K	N/A	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M
Δ_rS°	89.5	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	65.3 ± 6.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy of 22.0 eu assumed.; B

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
49.4	473.	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M

( • Hydrogen cyanide ) + = ( • 2)

By formula: (CHO₂^- • CHN) + CHN = (CHO₂^- • 2CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	74.5	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.	J/mol*K	N/A	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M
Δ_rS°	98.7	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	44.77	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
40.	350.	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M

CH₂N⁺ + Hydrogen cyanide = (CH₂N⁺ • )

By formula: CH₂N⁺ + CHN = (CH₂N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	109.	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; Δ_rH, Δ_rS too small compared with other nitrile dimers; M
Δ_rH°	126.	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.2	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; Δ_rH, Δ_rS too small compared with other nitrile dimers; M
Δ_rS°	130.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

(CH₂N⁺ • Hydrogen cyanide ) + = (CH₂N⁺ • 2)

By formula: (CH₂N⁺ • CHN) + CHN = (CH₂N⁺ • 2CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	57.7	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

(CH₂N⁺ • 2 Hydrogen cyanide ) + = (CH₂N⁺ • 3)

By formula: (CH₂N⁺ • 2CHN) + CHN = (CH₂N⁺ • 3CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	49.4	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

(CH₂N⁺ • 3 Hydrogen cyanide ) + = (CH₂N⁺ • 4)

By formula: (CH₂N⁺ • 3CHN) + CHN = (CH₂N⁺ • 4CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	38.	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	109.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; M

(CH₂N⁺ • Hydrogen cyanide • ) + = (CH₂N⁺ • 2 • )

By formula: (CH₂N⁺ • CHN • H₂O) + CHN = (CH₂N⁺ • 2CHN • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	65.3	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n, Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	N/A	Meot-Ner (Mautner) and Speller, 1989	gas phase; n, Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	35.	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n, Entropy change calculated or estimated; M

(CH₂N⁺ • ) + Hydrogen cyanide = (CH₂N⁺ • • )

By formula: (CH₂N⁺ • H₂O) + CHN = (CH₂N⁺ • CHN • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	78.7	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	85.4	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

(CH₂N⁺ • 2) + Hydrogen cyanide = (CH₂N⁺ • • 2)

By formula: (CH₂N⁺ • 2H₂O) + CHN = (CH₂N⁺ • CHN • 2H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	70.7	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	101.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

+ Hydrogen cyanide = ( • )

By formula: CH₃O⁺ + CHN = (CH₃O⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	86.2	kJ/mol	FA	Tanaka, Mackay, et al., 1978	gas phase; switching reaction(H2COH+)H2CO; Fehsenfeld, Dotan, et al., 1978, Cunningham, Payzant, et al., 1972; M

CH₄NO⁺ + Hydrogen cyanide = (CH₄NO⁺ • )

By formula: CH₄NO⁺ + CHN = (CH₄NO⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	80.8	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
40.	427.	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

CH₅O⁺ + Hydrogen cyanide = (CH₅O⁺ • )

By formula: CH₅O⁺ + CHN = (CH₅O⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	108.	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.5	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

CH₆N⁺ + Hydrogen cyanide = (CH₆N⁺ • )

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	87.0	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.8	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

CN^- + Hydrogen cyanide = (CN^- • )

By formula: CN^- + CHN = (CN^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	91. ± 15.	kJ/mol	IMRE	Larson and McMahon, 1987	gas phase; B,M
Δ_rH°	83.7 ± 8.4	kJ/mol	Est	Larson and McMahon, 1984	gas phase; B
Δ_rH°	86.6	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rH°	86.6	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	86.2	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rS°	86.2	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Δ_rS°	86.2	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Δ_rS°	113.	J/mol*K	N/A	Larson and McMahon, 1987	gas phase; switching reaction,Thermochemical ladder(H2O), Entropy change calculated or estimated; Payzant, Yamdagni, et al., 1971; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	60.7 ± 4.2	kJ/mol	TDAs	Meot-ner, 1988	gas phase; B
Δ_rG°	57.3 ± 9.6	kJ/mol	IMRE	Larson and McMahon, 1987	gas phase; B,M
Δ_rG°	60.7 ± 6.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • Hydrogen cyanide ) + = (CN^- • 2)

By formula: (CN^- • CHN) + CHN = (CN^- • 2CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	68.6	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rH°	68.6	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	91.2	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rS°	91.2	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Δ_rS°	91.2	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	41.4	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • 2 Hydrogen cyanide ) + = (CN^- • 3)

By formula: (CN^- • 2CHN) + CHN = (CN^- • 3CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	52.7	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rH°	52.7	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	88.7	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rS°	88.7	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Δ_rS°	88.7	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	26.4	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • 3 Hydrogen cyanide ) + = (CN^- • 4)

By formula: (CN^- • 3CHN) + CHN = (CN^- • 4CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	45.6	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rH°	45.6	kJ/mol	PHPMS	Meot-ner, 1988	gas phase; M,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	104.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rS°	104.	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Δ_rS°	104.	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	14.6	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • 4 Hydrogen cyanide ) + = (CN^- • 5)

By formula: (CN^- • 4CHN) + CHN = (CN^- • 5CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	41. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Δ_rH°	41.	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.5	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Δ_rS°	84.5	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.9	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • 5 Hydrogen cyanide ) + = (CN^- • 6)

By formula: (CN^- • 5CHN) + CHN = (CN^- • 6CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	85.4	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.0	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

(CN^- • 6 Hydrogen cyanide ) + = (CN^- • 7)

By formula: (CN^- • 6CHN) + CHN = (CN^- • 7CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	32. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	N/A	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	6.69	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
13.	238.	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M

(CN^- • Hydrogen cyanide • ) + = (CN^- • 2 • )

By formula: (CN^- • CHN • H₂O) + CHN = (CN^- • 2CHN • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	55.2	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	74.5	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

(CN^- • Hydrogen cyanide • 2) + = (CN^- • 2 • 2)

By formula: (CN^- • CHN • 2H₂O) + CHN = (CN^- • 2CHN • 2H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	52.7	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
31.	262.	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

(CN^- • 2 Hydrogen cyanide • ) + = (CN^- • 3 • )

By formula: (CN^- • 2CHN • H₂O) + CHN = (CN^- • 3CHN • H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.5	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
30.	262.	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

(CN^- • 3) + Hydrogen cyanide = (CN^- • • 3)

By formula: (CN^- • 3H₂O) + CHN = (CN^- • CHN • 3H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	54.8	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
33.	262.	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

+ Hydrogen cyanide = ( • )

By formula: C₂H₃O₂^- + CHN = (C₂H₃O₂^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	92.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	98.3	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M

( • Hydrogen cyanide ) + = ( • 2)

By formula: (C₂H₃O₂^- • CHN) + CHN = (C₂H₃O₂^- • 2CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	69.5 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.5	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	44.35	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 2 Hydrogen cyanide ) + = ( • 3)

By formula: (C₂H₃O₂^- • 2CHN) + CHN = (C₂H₃O₂^- • 3CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	61.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	107.	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	30.1	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 3 Hydrogen cyanide ) + = ( • 4)

By formula: (C₂H₃O₂^- • 3CHN) + CHN = (C₂H₃O₂^- • 4CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	50.2 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	114.	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	16.3	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 4 Hydrogen cyanide ) + = ( • 5)

By formula: (C₂H₃O₂^- • 4CHN) + CHN = (C₂H₃O₂^- • 5CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	41. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	N/A	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.0	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
19.	213.	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M

C₂H₄N⁺ + Hydrogen cyanide = (C₂H₄N⁺ • )

By formula: C₂H₄N⁺ + CHN = (C₂H₄N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	92.5	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; CD3CNH+; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.7	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; CD3CNH+; M

C₂H₅O⁺ + Hydrogen cyanide = (C₂H₅O⁺ • )

By formula: C₂H₅O⁺ + CHN = (C₂H₅O⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	96.2	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	90.8	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₃H₂N⁺ + Hydrogen cyanide = (C₃H₂N⁺ • )

By formula: C₃H₂N⁺ + CHN = (C₃H₂N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	99.6	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	107.	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

+ Hydrogen cyanide = ( • )

By formula: C₃H₃N₂^- + CHN = (C₃H₃N₂^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	100.	kJ/mol	PHPMS	Meot-Ner (Mautner), 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	91.6	J/mol*K	PHPMS	Meot-Ner (Mautner), 1988	gas phase; M

C₃H₇⁺ + Hydrogen cyanide = (C₃H₇⁺ • )

By formula: C₃H₇⁺ + CHN = (C₃H₇⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	166.	kJ/mol	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; condensation; M
Δ_rH°	129.	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; forms i-C3H7NCH+; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	189.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Sieck, 1991	gas phase; condensation; M
Δ_rS°	130.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; forms i-C3H7NCH+; M

C₃H₇O⁺ + Hydrogen cyanide = (C₃H₇O⁺ • )

By formula: C₃H₇O⁺ + CHN = (C₃H₇O⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	85.4	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	98.7	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₃H₁₀N⁺ + Hydrogen cyanide = (C₃H₁₀N⁺ • )

By formula: C₃H₁₀N⁺ + CHN = (C₃H₁₀N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	70.3	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.2	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₄H₈N⁺ + Hydrogen cyanide = (C₄H₈N⁺ • )

By formula: C₄H₈N⁺ + CHN = (C₄H₈N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	84.1	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	94.1	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₄H₉⁺ + Hydrogen cyanide = (C₄H₉⁺ • )

By formula: C₄H₉⁺ + CHN = (C₄H₉⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	68.2	kJ/mol	PHPMS	Meot-Ner (Mautner), 1978	gas phase; may form t-C4H9NCH+; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	PHPMS	Meot-Ner (Mautner), 1978	gas phase; may form t-C4H9NCH+; M

C₄H₉O₂⁺ + Hydrogen cyanide = (C₄H₉O₂⁺ • )

By formula: C₄H₉O₂⁺ + CHN = (C₄H₉O₂⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	79.5	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.	J/mol*K	N/A	Speller and Meot-Ner (Mautner), 1985	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
33.	455.	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; Entropy change calculated or estimated; M

C₄H₁₀NO⁺ + Hydrogen cyanide = (C₄H₁₀NO⁺ • )

By formula: C₄H₁₀NO⁺ + CHN = (C₄H₁₀NO⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	66.1	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.4	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₇H₁₁O⁺ + Hydrogen cyanide = (C₇H₁₁O⁺ • )

By formula: C₇H₁₁O⁺ + CHN = (C₇H₁₁O⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	73.6	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	97.1	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

C₉H₂₂N⁺ + Hydrogen cyanide = (C₉H₂₂N⁺ • )

By formula: C₉H₂₂N⁺ + CHN = (C₉H₂₂N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	57.7	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	121.	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

+ Hydrogen cyanide = ( • )

By formula: Cl^- + CHN = (Cl^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	91.2 ± 4.2	kJ/mol	TDAs	Meot-ner, 1988	gas phase; B,B,M
Δ_rH°	87.9 ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1984, 2	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	79.1	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Δ_rS°	99.2	J/mol*K	N/A	Larson and McMahon, 1984, 3	gas phase; switching reaction(Cl-)t-C4H9OH, Entropy change calculated or estimated; French, Ikuta, et al., 1982; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	67.8 ± 6.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B
Δ_rG°	67.4 ± 4.2	kJ/mol	TDAs	Meot-ner, 1988	gas phase; B
Δ_rG°	58.2 ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1984, 2	gas phase; B,M

( • Hydrogen cyanide ) + = ( • 2)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	74.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.0	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	46.44	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 2 Hydrogen cyanide ) + = ( • 3)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	56.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	89.5	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	30.1	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 3 Hydrogen cyanide ) + = ( • 4)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	97.9	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	17.6	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 4 Hydrogen cyanide ) + = ( • 5)

By formula: (Cl^- • 4CHN) + CHN = (Cl^- • 5CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	37. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	89.1	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.5	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 5 Hydrogen cyanide ) + = ( • 6)

By formula: (Cl^- • 5CHN) + CHN = (Cl^- • 6CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	102.	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	6.28	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 6 Hydrogen cyanide ) + = ( • 7)

By formula: (Cl^- • 6CHN) + CHN = (Cl^- • 7CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	33. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	96.7	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	4.18	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 7 Hydrogen cyanide ) + = ( • 8)

By formula: (Cl^- • 7CHN) + CHN = (Cl^- • 8CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	34. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	115.	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.1 ± 9.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 8 Hydrogen cyanide ) + = ( • 9)

By formula: (Cl^- • 8CHN) + CHN = (Cl^- • 9CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	31. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	N/A	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	0.42	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy estimated; B

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
13.	171.	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; Entropy change calculated or estimated; M

+ Hydrogen cyanide = ( • )

By formula: F^- + CHN = (F^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	165. ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1983	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.9	J/mol*K	N/A	Larson and McMahon, 1983	gas phase; switching reaction(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	138. ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1983	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M

HS^- + Hydrogen cyanide = (HS^- • )

By formula: HS^- + CHN = (HS^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	87.9 ± 4.2	kJ/mol	IMRE	Meot-ner, 1988	gas phase; See also H2S..CN-; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	PHPMS	Meot-ner, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	62.8 ± 4.2	kJ/mol	IMRE	Meot-ner, 1988	gas phase; See also H2S..CN-; B

( • 2) + Hydrogen cyanide = ( • • 2)

By formula: (H₃O⁺ • 2H₂O) + CHN = (H₃O⁺ • CHN • 2H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	82.8	kJ/mol	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	123.	J/mol*K	PHPMS	Meot-Ner (Mautner) and Speller, 1989	gas phase; n; M

+ Hydrogen cyanide = ( • )

By formula: H₄N⁺ + CHN = (H₄N⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	91.6	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Δ_rH°	85.8	kJ/mol	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	97.9	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Δ_rS°	84.5	J/mol*K	PHPMS	Speller and Meot-Ner (Mautner), 1985	gas phase; M

( • Hydrogen cyanide ) + = ( • 2)

By formula: (H₄N⁺ • CHN) + CHN = (H₄N⁺ • 2CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	72.8	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	97.9	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 2 Hydrogen cyanide ) + = ( • 3)

By formula: (H₄N⁺ • 2CHN) + CHN = (H₄N⁺ • 3CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	57.3	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	90.0	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 3 Hydrogen cyanide ) + = ( • 4)

By formula: (H₄N⁺ • 3CHN) + CHN = (H₄N⁺ • 4CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.0	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	87.4	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 4 Hydrogen cyanide ) + = ( • 5)

By formula: (H₄N⁺ • 4CHN) + CHN = (H₄N⁺ • 5CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	33.	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	79.1	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 5 Hydrogen cyanide ) + = ( • 6)

By formula: (H₄N⁺ • 5CHN) + CHN = (H₄N⁺ • 6CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	31.	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	83.3	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • Hydrogen cyanide • ) + = ( • 2 • )

By formula: (H₄N⁺ • CHN • H₃N) + CHN = (H₄N⁺ • 2CHN • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	51.0	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	81.2	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • Hydrogen cyanide • 2) + = ( • 2 • 2)

By formula: (H₄N⁺ • CHN • 2H₃N) + CHN = (H₄N⁺ • 2CHN • 2H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.9	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
21.	315.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

( • 2 Hydrogen cyanide • ) + = ( • 3 • )

By formula: (H₄N⁺ • 2CHN • H₃N) + CHN = (H₄N⁺ • 3CHN • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	53.6	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	101.	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 3 Hydrogen cyanide • ) + = ( • 4 • )

By formula: (H₄N⁺ • 3CHN • H₃N) + CHN = (H₄N⁺ • 4CHN • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
11.	292.	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated, T = 392 in paper is error; M

( • ) + Hydrogen cyanide = ( • • )

By formula: (H₄N⁺ • H₃N) + CHN = (H₄N⁺ • CHN • H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	59.4	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	77.4	J/mol*K	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; M

( • 2) + Hydrogen cyanide = ( • • 2)

By formula: (H₄N⁺ • 2H₃N) + CHN = (H₄N⁺ • CHN • 2H₃N)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	56.1	kJ/mol	PHPMS	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	76.6	J/mol*K	N/A	Deakyne, Knuth, et al., 1994	gas phase; Entropy change calculated or estimated; M

+ Hydrogen cyanide = ( • )

By formula: I^- + CHN = (I^- • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	70.3 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	88.7	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	43.5 ± 6.7	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • Hydrogen cyanide ) + = ( • 2)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	55.2 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	83.7	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	30.1	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 2 Hydrogen cyanide ) + = ( • 3)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.9 ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	87.9	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	20.5	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 3 Hydrogen cyanide ) + = ( • 4)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	38. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.9	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.4	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 4 Hydrogen cyanide ) + = ( • 5)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.8	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	7.53	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 5 Hydrogen cyanide ) + = ( • 6)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	31. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	83.3	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	6.28	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 6 Hydrogen cyanide ) + = ( • 7)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	31. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	83.3	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	6.28	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

( • 7 Hydrogen cyanide ) + = ( • 8)

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

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	28. ± 4.2	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	88.7	J/mol*K	PHPMS	Meot-ner, Cybulski, et al., 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	2.1	kJ/mol	TDAs	Meot-ner, Cybulski, et al., 1988	gas phase; B

+ Hydrogen cyanide = ( • )

By formula: Li⁺ + CHN = (Li⁺ • CHN)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	152.	kJ/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Δ_rH°	150.	kJ/mol	ICR	Staley and Beauchamp, 1975	gas phase; switching reaction(Li+)H2O, from graph; Dzidic and Kebarle, 1970 extrapolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	100.	J/mol*K	N/A	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	120.	kJ/mol	ICR	Woodin and Beauchamp, 1978	gas phase; switching reaction(Li+)H2O, Entropy change calculated or estimated; Dzidic and Kebarle, 1970 interpolated; M

Mass spectrum (electron ionization)

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

Spectrum

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References

Go To: Top, Ion clustering data, Mass spectrum (electron ionization), Notes

Meot-ner, Cybulski, et al., 1988
Meot-ner, M.; Cybulski, S.M.; Scheiner, S.; Liebman, J.F., Is CN^- Significantly Anisotropic? Comparison of CN^- vs. Cl^-: Clustering with HCN and Condensed Phase Thermochemistry, J. Phys. Chem., 1988, 92, 10, 2738, https://doi.org/10.1021/j100321a009 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Gas phase bihalide and pseudohalide ions. An ICR determination of hydrogen bond energies in XHY- species (X,Y = F, Cl, Br, CN), Inorg. Chem., 1984, 23, 2029. [all data]

Meot-ner, 1988
Meot-ner, M., Ionic Hydrogen Bond and Ion Solvation. ₆. Interaction Energies of the Acetate Ion with Organic Molecules. Comparison of CH₃COO^- with Cl^-, CN^-, and SH^-, J. Am. Chem. Soc., 1988, 110, 12, 3854, https://doi.org/10.1021/ja00220a022 . [all data]

Speller and Meot-Ner (Mautner), 1985
Speller, C.V.; Meot-Ner (Mautner), M., The Ionic Hydrogen Bond and Ion Solvation. 3. Bonds Involving Cyanides. Correlations with Proton Affinites, J. Phys. Chem., 1985, 81, 24, 5217, https://doi.org/10.1021/j100270a020 . [all data]

Meot-Ner (Mautner), 1978
Meot-Ner (Mautner), M., Solvation of the Proton by HCN and CH3CN. Condensation of HCN with Ions in the Gas Phase., J. Am. Chem. Soc., 1978, 100, 15, 4694, https://doi.org/10.1021/ja00483a012 . [all data]

Meot-Ner (Mautner) and Speller, 1989
Meot-Ner (Mautner), M.; Speller, C.V., Multicomponent Cluster Ions.3. Comparative Stabilities of Cationic and Anionic Hydrogen Bonded Networks. Mixed Clusters of Water and Hydrogen Cyanide, J. Phys. Chem., 1989, 93, 6580. [all data]

Tanaka, Mackay, et al., 1978
Tanaka, K.; Mackay, G.I.; Bohme, D.K., Rate and Equilibrium Constant Measurements for Gas-Phase Proton-Transfer Reactions Involving H2O, H2S, HCN, and H2CO, Can. J. Chem., 1978, 56, 2, 193, https://doi.org/10.1139/v78-031 . [all data]

Fehsenfeld, Dotan, et al., 1978
Fehsenfeld, F.C.; Dotan, I.; Albritton, D.L.; Howard, C.J.; Ferguson, E.E., Stratospheric Positive Ion Chemistry of Formaldehyde and Methanol, J. Geophys. Res., 1978, 83, C3, 1333, https://doi.org/10.1029/JC083iC03p01333 . [all data]

Cunningham, Payzant, et al., 1972
Cunningham, A.J.; Payzant, J.D.; Kebarle, P., A Kinetic Study of the Proton Hydrate H+(H2O)n Equilibria in the Gas Phase, J. Am. Chem. Soc., 1972, 94, 22, 7627, https://doi.org/10.1021/ja00777a003 . [all data]

Larson and McMahon, 1987
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. The energetics of interaction between cyanide ion and bronsted acids, J. Am. Chem. Soc., 1987, 109, 6230. [all data]

Payzant, Yamdagni, et al., 1971
Payzant, J.D.; Yamdagni, R.; Kebarle, P., Hydration of CN-, NO₂-, NO₃-, and HO- in the gas phase, Can. J. Chem., 1971, 49, 3308. [all data]

Meot-Ner (Mautner), 1988
Meot-Ner (Mautner), M., Models for Strong Interactions in Proteins and Enzymes. 2. Interactions of Ions with the Peptide Link and Imidazole, J. Am. Chem. Soc., 1988, 110, 10, 3075, https://doi.org/10.1021/ja00218a014 . [all data]

Meot-Ner (Mautner) and Sieck, 1991
Meot-Ner (Mautner), M.; Sieck, L.W., Proton affinity ladders from variable-temperature equilibrium measurements. 1. A reevaluation of the upper proton affinity range, J. Am. Chem. Soc., 1991, 113, 12, 4448, https://doi.org/10.1021/ja00012a012 . [all data]

Larson and McMahon, 1984, 2
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. An experimental investigation of the interaction between chloride ion and bronsted acids from ICR chloride exchange equilibria, J. Am. Chem. Soc., 1984, 106, 517. [all data]

Larson and McMahon, 1984, 3
Larson, J.W.; McMahon, T.B., Gas phase negative ion chemistry of alkylchloroformates, Can. J. Chem., 1984, 62, 675. [all data]

French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P., Hydrogen bonding of O-H and C-H hydrogen donors to Cl^-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl^- = RHCl^-, Can. J. Chem., 1982, 60, 1907. [all data]

Larson and McMahon, 1983
Larson, J.W.; McMahon, T.B., Strong hydrogen bonding in gas-phase anions. An ion cyclotron resonance determination of fluoride binding energetics to bronsted acids from gas-phase fluoride exchange equilibria measurements, J. Am. Chem. Soc., 1983, 105, 2944. [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R., Bond dissociation energies of F2(-) and HF2(-). A gas-phase experimental and G2 theoretical study, J. Phys. Chem., 1995, 99, 7, 2002, https://doi.org/10.1021/j100007a034 . [all data]

Arshadi, Yamdagni, et al., 1970
Arshadi, M.; Yamdagni, R.; Kebarle, P., Hydration of Halide Negative Ions in the Gas Phase. II. Comparison of Hydration Energies for the Alkali Positive and Halide Negative Ions, J. Phys. Chem., 1970, 74, 7, 1475, https://doi.org/10.1021/j100702a014 . [all data]

Deakyne, Knuth, et al., 1994
Deakyne, C.A.; Knuth, D.M.; Speller, C.V.; Meot-Ner (Mautner), M.; Sieck, L.W., Filling of Solvent Shells about Ions. Part 3. Isomeric Clusters of (HCN)n(NH3)mH+, J. Mol. Structure (Theochem), 1994, 307, 217, https://doi.org/10.1016/0166-1280(94)80130-4 . [all data]

Woodin and Beauchamp, 1978
Woodin, R.L.; Beauchamp, J.L., Bonding of Li+ to Lewis Bases in the Gas Phase. Reversals in Methyl Substituent Effects for Different Reference Acids, J. Am. Chem. Soc., 1978, 100, 2, 501, https://doi.org/10.1021/ja00470a024 . [all data]

Dzidic and Kebarle, 1970
Dzidic, I.; Kebarle, P., Hydration of the Alkali Ions in the Gas Phase. Enthalpies and Entropies of Reactions M+(H2O)n-1 + H2O = M+(H2O)n, J. Phys. Chem., 1970, 74, 7, 1466, https://doi.org/10.1021/j100702a013 . [all data]

Staley and Beauchamp, 1975
Staley, R.H.; Beauchamp, J.L., Intrinsic Acid - Base Properties of Molecules. Binding Energies of Li+ to pi - and n - Donor Bases, J. Am. Chem. Soc., 1975, 97, 20, 5920, https://doi.org/10.1021/ja00853a050 . [all data]

Notes

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Symbols used in this document:

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

Hydrogen cyanide

Data at NIST subscription sites:

Ion clustering data

Clustering reactions

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Free energy of reaction

Mass spectrum (electron ionization)

Spectrum

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Notes

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