Iodine
- Formula: I2
- Molecular weight: 253.80894
- IUPAC Standard InChIKey: PNDPGZBMCMUPRI-UHFFFAOYSA-N
- CAS Registry Number: 7553-56-2
- 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. - Other names: I2; Eranol; Iode; Iodine-127; Iodio; Iosan Superdip; Jod; Jood; Molecular iodine; Tincture iodine; Vistarin; Iodine crystals; Iodine sublimed; Diiodine; Diatomic iodine
- 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 / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
- NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)
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.
Ion clustering 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 as indicated in comments:
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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: I- + I2 = (I- • I2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 24.0 | kcal/mol | N/A | Downs and Adams, 1973 | gas phase; from ΔrH(f); M |
+ = I3-
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 32.5 ± 2.4 | kcal/mol | N/A | Taylor, Asmis, et al., 1999 | gas phase; B |
ΔrH° | 30.1 ± 1.4 | kcal/mol | CIDT | Do, Klein, et al., 1997 | gas phase; B |
ΔrH° | 85.10 | kcal/mol | Ther | Finch, Gates, et al., 1977 | gas phase; This value is far more bound than expected from other studies; B |
ΔrH° | 32.60 | kcal/mol | N/A | Check, Faust, et al., 2001 | gas phase; FeF3-(t); ; ΔS(EA)=2.8; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 22.50 | kcal/mol | N/A | Check, Faust, et al., 2001 | gas phase; FeF3-(t); ; ΔS(EA)=2.8; B |
By formula: I3- + I2 = (I3- • I2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 11.7 ± 1.4 | kcal/mol | CIDT | Do, Klein, et al., 1997 | gas phase; B |
References
Go To: Top, Ion clustering data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Downs and Adams, 1973
Downs, A.J.; Adams, G.J.,
Comprehensive Inorganic Chemistry, J. C. Bailar, H. J. Emeleus, R. Nyholm and A. F. Trotman - Dickerson, ed(s)., Pergamon Press, New York, 1973, 1543. [all data]
Taylor, Asmis, et al., 1999
Taylor, T.R.; Asmis, K.R.; Zanni, M.T.; Neumark, D.M.,
Characterization of the I-3 radical by anion photoelectron spectroscopy,
J. Chem. Phys., 1999, 110, 16, 7607-7609, https://doi.org/10.1063/1.478672
. [all data]
Do, Klein, et al., 1997
Do, K.; Klein, T.P.; Pommerening, C.A.; Sunderlin, L.S.,
A New Flowing Afterglow-Guided Ion Beam Tandem Mass Spectrometer. Applications to the Thermochemistry of Polyiodide Ions,
J. Am. Soc. Mass Spectrom., 1997, 8, 7, 688, https://doi.org/10.1016/S1044-0305(97)00116-5
. [all data]
Finch, Gates, et al., 1977
Finch, A.; Gates, P.N.; Peake, S.J.,
Thermochemistry of polyhalides. III. Cesium and rubidium tetrachloroiodates,
J. Inorg. Nucl. Chem., 1977, 39, 2135. [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, Ion clustering 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
- 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.