Isothiocyanic acid
- Formula: CHNS
- Molecular weight: 59.090
- IUPAC Standard InChI: InChI=1S/CNS/c2-1-3/q-1
- IUPAC Standard InChIKey: ZBKFYXZXZJPWNQ-UHFFFAOYSA-N
- CAS Registry Number: 3129-90-6
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
Gas phase ion energetics 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 evaluated as indicated in comments:
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to CHNS+ (ion structure unspecified)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| IE (evaluated) | ≤9.92 | eV | N/A | N/A | L |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| ≤9.92 | PI | Ruscic and Berkowitz, 1994 | LL |
| 10.1 ± 0.1 | PE | Eland, 1970 | RDSH |
| 9.94 ± 0.02 | PE | Cradock, Ebsworth, et al., 1972 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| NCS+ | 14.903 ± 0.009 | H | PI | Ruscic and Berkowitz, 1994 | LL |
| CS+ | 16.884 | ? | PI | Ruscic and Berkowitz, 1994 | LL |
| HS+ | 15.131 | CN | PI | Ruscic and Berkowitz, 1994 | LL |
| NS+ | 16.879 | ? | PI | Ruscic and Berkowitz, 1994 | LL |
| S+ | 13.205 ± 0.014 | ? | PI | Ruscic and Berkowitz, 1994 | LL |
De-protonation reactions
CNS- + =
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | <1361. ± 4.6 | kJ/mol | D-EA | Bradforth, Kim, et al., 1993 | gas phase; Acid HNCS. HSCN up by ca. 8 kcal/mol; B |
| ΔrH° | 1375. ± 21. | kJ/mol | G+TS | Bierbaum, Grabowski, et al., 1984 | gas phase; Acid: HNCS; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | <1329. ± 5.9 | kJ/mol | H-TS | Bradforth, Kim, et al., 1993 | gas phase; Acid HNCS. HSCN up by ca. 8 kcal/mol; B |
| ΔrG° | 1343. ± 21. | kJ/mol | IMRB | Bierbaum, Grabowski, et al., 1984 | gas phase; Acid: HNCS; B |
References
Go To: Top, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Ruscic and Berkowitz, 1994
Ruscic, B.; Berkowitz, J.,
The H-NCS bond energy, Hf(NCS), and IP(NCS) from photoionization mass spectrometric studies of HNCS, NCS, and (NCS)2,
J. Chem. Phys., 1994, 101, 7975. [all data]
Eland, 1970
Eland, J.H.D.,
The photoelectron spectra of isocyanic acid and related compounds,
Phil. Trans. Roy. Soc. (London), 1970, A268, 87. [all data]
Cradock, Ebsworth, et al., 1972
Cradock, S.; Ebsworth, E.A.V.; Murdoch, J.D.,
Photoelectron spectra of some Group 4 pseudohalides and related compounds,
J. Chem. Soc. Faraday Trans. 2, 1972, 68, 86. [all data]
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]
Bierbaum, Grabowski, et al., 1984
Bierbaum, V.M.; Grabowski, J.J.; DePuy, C.H.,
Gas-phase synthesis and reactions of nitrogen- and sulfur-containing anions,
J. Phys. Chem., 1984, 88, 1389. [all data]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy 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
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.