Selected ATcT [1, 2] enthalpy of formation based on version 1.122e of the Thermochemical Network [3]

This version of ATcT results was generated from an expansion of version 1.122d [4] to include chemical species related to methyl acetate and methyl formate [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Iodine atomI (g, 2P1/2)[I]198.109197.709± 0.0021kJ/mol126.904470 ±

Representative Geometry of I (g, 2P1/2)

spin ON           spin OFF

Top contributors to the provenance of ΔfH° of I (g, 2P1/2)

The 5 contributors listed below account for 93.2% of the provenance of ΔfH° of I (g, 2P1/2).

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Reaction Measured Quantity Reference
21.81064.2 I2 (cr,l) → I2 (g) ΔrG°(298.15 K) = 4.616 ± 0.002 kcal/molGiauque 1931, Baxter 1915, Baxter 1907, 3rd Law, est unc
21.81064.4 I2 (cr,l) → I2 (g) ΔrG°(298.15 K) = 4.618 ± 0.002 kcal/molGerry 1932, Giauque 1931, 3rd Law, est unc
21.81069.6 I2 (cr,l) → I2 (g) ΔrH°(298.15 K) = 14.919 ± 0.002 kcal/molShirley 1959, Baxter 1907, Baxter 1915, 2nd Law
21.81069.8 I2 (cr,l) → I2 (g) ΔrH°(325.8 K) = 14.799 ± 0.002 kcal/molShirley 1959, Baxter 1907, Baxter 1915, 2nd Law
5.91063.8 I2 (cr,l) → I2 (g) ΔrG°(298.15 K) = 4.614 ± 0.002 (×1.915) kcal/molBaxter 1915, Baxter 1907, 3rd Law

Top 10 species with enthalpies of formation correlated to the ΔfH° of I (g, 2P1/2)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
99.9 Iodine atomI (g, 2P3/2)[I]107.157106.757± 0.0021kJ/mol126.904470 ±
99.9 Iodine atomI (g)[I]107.157106.757± 0.0021kJ/mol126.904470 ±
99.9 DiiodineI2 (g)II65.49762.417± 0.0041kJ/mol253.808940 ±
89.7 IodideI- (g)[I-]-187.995-188.396± 0.0021kJ/mol126.905019 ±
31.1 Iodine atom cationI+ (g)[I+]1115.5491115.149± 0.0062kJ/mol126.903921 ±
22.5 Diiodine cation[I2]+ (g)I[I+]963.523960.408± 0.018kJ/mol253.808391 ±
16.1 Iodine monochlorideICl (g)ICl19.02417.391± 0.013kJ/mol162.35717 ±
5.4 Hydrogen iodideHI (g)I28.64526.469± 0.036kJ/mol127.912410 ±
3.1 Iodine monochlorideICl (cr)ICl-36.511-35.537± 0.063kJ/mol162.35717 ±
3.1 Iodine monochlorideICl (cr,l)ICl-36.511-35.537± 0.063kJ/mol162.35717 ±

Most Influential reactions involving I (g, 2P1/2)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Reaction Measured Quantity Reference
0.9991081.2 I (g, 2P3/2) → I (g, 2P1/2) ΔrH°(0 K) = 7602.977 ± 0.003 cm-1Luc-Koenig 1973
0.4461082.9 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.176 ± 0.016 cm-1Gerstenkorn 1983
0.3161082.11 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.159 ± 0.019 cm-1Tromp 1983
0.0961082.4 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.208 ± 0.033 (×1.044) cm-1Barrow 1973
0.0531082.5 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.220 ± 0.015 (×3.084) cm-1Barrow 1973
0.0451082.12 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.208 ± 0.05 cm-1Tromp 1985, est unc
0.0171082.7 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.122 ± 0.080 cm-1Danyluk 1976, Danyluk 1977, note unc3
0.0091082.13 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.064 ± 0.02 (×5.536) cm-1King 1980, est unc
0.0081082.8 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20043.063 ± 0.020 (×5.657) cm-1Danyluk 1977
0.0001081.1 I (g, 2P3/2) → I (g, 2P1/2) ΔrH°(0 K) = 7603.15 ± 0.05 (×3.513) cm-1Moore NSRDS-NBS 35, est unc
0.0001082.3 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20044.0 ± 1.2 cm-1LeRoy 1971
0.0001082.1 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20037 ± 8 cm-1Brown 1931
0.0001082.6 I2 (g) → I (g, 2P3/2) I (g, 2P1/2) ΔrH°(0 K) = 20055.6 ± 10 (×1.269) cm-1Steinfeld 1969, Verma 1960, est unc

References (for your convenience, also available in RIS and BibTex format)
1   B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner,
Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited.
J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2   B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner,
Active Thermochemical Tables: Thermochemistry for the 21st Century.
J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3   B. Ruscic and D. H. Bross,
Active Thermochemical Tables (ATcT) values based on ver. 1.122e of the Thermochemical Network, Argonne National Laboratory (2019); available at
4   L. Cheng, J. Gauss, B. Ruscic, P. Armentrout, and J. Stanton,
Bond Dissociation Energies for Diatomic Molecules Containing 3d Transition Metals: Benchmark Scalar-Relativistic Coupled-Cluster Calculations for Twenty Molecules.
J. Chem. Theory Comput. 13, 1044-1056 (2017) [DOI: 10.1021/acs.jctc.6b00970]
5   J. P. Porterfield, D. H. Bross, B. Ruscic, J. H. Thorpe, T. L. Nguyen, J. H. Baraban, J. F. Stanton, J. W. Daily, and G. B. Ellison,
Thermal Decomposition of Potential Ester Biofuels, Part I: Methyl Acetate and Methyl Butanoate.
J. Chem. Phys. A 121, 4658-4677 (2017) [DOI: 10.1021/acs.jpca.7b02639] (Veronica Vaida Festschrift)
6   B. Ruscic,
Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables.
Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.0005 kJ/mol.

Website Functionality Credits
The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D.

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.