Hydrogen iodide
- Formula: HI
- Molecular weight: 127.91241
- IUPAC Standard InChI: InChI=1S/HI/h1H
- IUPAC Standard InChIKey: XMBWDFGMSWQBCA-UHFFFAOYSA-N
- CAS Registry Number: 10034-85-2
- 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:
- Data at other public NIST sites:
- Options:
Data at NIST subscription sites:
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
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:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
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 HI+ (ion structure unspecified)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| IE (evaluated) | 10.386 ± 0.001 | eV | N/A | N/A | L |
| Quantity | Value | Units | Method | Reference | Comment |
| Proton affinity (review) | 627.5 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
| Quantity | Value | Units | Method | Reference | Comment |
| Gas basicity | 601.3 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 10.38 | PE | Kimura, Katsumata, et al., 1981 | LLK |
| 10.386 ± 0.001 | S | Eland and Berkowitz, 1977 | LLK |
| 10.38 ± 0.01 | PE | Lempka, Passmore, et al., 1968 | RDSH |
| 10.42 ± 0.01 | PE | Frost, McDowell, et al., 1967 | RDSH |
| 10.38 ± 0.02 | PI | Watanabe, 1957 | RDSH |
| 10.3 ± 0.1 | EI | Friedman, 1955 | RDSH |
| ~10.39 | S | Price, 1938 | RDSH |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| I+ | 13.49 ± 0.13 | ? | PI | Eland and Berkowitz, 1977 | LLK |
De-protonation reactions
+
=
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1315.24 ± 0.084 | kJ/mol | D-EA | Pelaez, Blondel, et al., 2009 | gas phase; Given: 3.0590463(38) eV; B |
| ΔrH° | 1312.1 | kJ/mol | N/A | Check, Faust, et al., 2001 | gas phase; Fe(CO)2-(q); ; ΔS(EA)=5.0; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1294.03 ± 0.25 | kJ/mol | H-TS | Pelaez, Blondel, et al., 2009 | gas phase; Given: 3.0590463(38) eV; B |
| ΔrG° | 1290.8 | kJ/mol | N/A | Check, Faust, et al., 2001 | gas phase; Fe(CO)2-(q); ; ΔS(EA)=5.0; 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.
Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,
Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,
J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018
. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Eland and Berkowitz, 1977
Eland, J.H.D.; Berkowitz, J.,
Photoionization mass spectrometry of HI and DI at high resolution,
J. Chem. Phys., 1977, 67, 5034. [all data]
Lempka, Passmore, et al., 1968
Lempka, H.J.; Passmore, T.R.; Price, W.C.,
The photoelectron spectra and ionized states of the halogen acids,
Proc. Roy. Soc. (London), 1968, A304, 53. [all data]
Frost, McDowell, et al., 1967
Frost, D.C.; McDowell, C.A.; Vroom, D.A.,
Photoelectron spectra of the halogens and the hydrogen halides,
J. Chem. Phys., 1967, 46, 4255. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Friedman, 1955
Friedman, L.,
Mass spectrum of lithium iodide,
J. Chem. Phys., 1955, 23, 477. [all data]
Price, 1938
Price, W.C.,
The absorption spectra of the halogen acids in the vacuum ultra-violet,
Proc. Roy. Soc. (London), 1938, A167, 216. [all data]
Pelaez, Blondel, et al., 2009
Pelaez, R.J.; Blondel, C.; Delsart, C.; Drag, C.,
Pulsed photodetachment microscopy and the electron affinity of iodine,
J. Phys. B: Atom. Mol. Opt. Phys., 2009, 42, 12, 125001, https://doi.org/10.1088/0953-4075/42/12/125001
. [all data]
Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S.,
Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements,
J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l
. [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.