Isocyanic acid
- Formula: CHNO
- Molecular weight: 43.0247
- IUPAC Standard InChI: InChI=1S/CHNO/c2-1-3/h2H
- IUPAC Standard InChIKey: OWIKHYCFFJSOEH-UHFFFAOYSA-N
- CAS Registry Number: 75-13-8
- Chemical structure:
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Reaction thermochemistry data
Go To: Top, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: 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.
Individual Reactions
CNO- + =
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1427.5 ± 2.6 | kJ/mol | D-EA | Bradforth, Kim, et al., 1993 | gas phase; D-EA cycle requires a DH ca 4 kcal/mol weaker |
| ΔrH° | 1442. ± 8.8 | kJ/mol | G+TS | Wight and Beauchamp, 1980 | gas phase |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1400.6 ± 3.0 | kJ/mol | H-TS | Bradforth, Kim, et al., 1993 | gas phase; D-EA cycle requires a DH ca 4 kcal/mol weaker |
| ΔrG° | 1415. ± 8.4 | kJ/mol | IMRE | Wight and Beauchamp, 1980 | gas phase |
(CAS Reg. No. 1140500-24-8 • 4294967295) +
= CAS Reg. No. 1140500-24-8
By formula: (CAS Reg. No. 1140500-24-8 • 4294967295CHNO) + CHNO = CAS Reg. No. 1140500-24-8
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 180. ± 13. | kJ/mol | N/A | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale |
(CAS Reg. No. 67131-48-0 • 4294967295) +
= CAS Reg. No. 67131-48-0
By formula: (CAS Reg. No. 67131-48-0 • 4294967295CHNO) + CHNO = CAS Reg. No. 67131-48-0
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 243. ± 9.2 | kJ/mol | N/A | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale |
References
Go To: Top, Reaction thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Bradforth, Kim, et al., 1993
Bradforth, S.E.; Kim, E.H.; Arnold, D.W.; Neumark, D.M.,
Photoelectron Spectroscopy of CN-, NCO-, and NCS-,
J. Chem. Phys., 1993, 98, 2, 800, https://doi.org/10.1063/1.464244
. [all data]
Wight and Beauchamp, 1980
Wight, C.A.; Beauchamp, J.L.,
Acidity, basicity, and ion/molecule reactions of isocyanic acid in the gas phase by ICR spectroscopy,
J. Phys. Chem., 1980, 84, 2503. [all data]
Taft, 1987
Taft, R.W.,
The Nature and Analysis of Substitutent Electronic Effects,
Personal communication. See also Prog. Phys. Org. Chem., 1987, 16, 1. [all data]
Notes
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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