Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

cis-1,2-Diiodoethene

Formula: CHICHI (g, cis)

CAS RN: 590-26-1

ATcT ID: 590-26-1*0

SMILES: C(\I)=C\I

InChI: InChI=1S/C2H2I2/c3-1-2-4/h1-2H/b2-1-

InChIKey: CVOGMKGEVNGRSK-UPHRSURJSA-N

Hills Formula: C2H2I2

2D Image:

$C(\I)=C\I$

Aliases: cis-1,2-Diiodoethene; cis-1,2-Diiodoethylene; cis-Diiodoethene; cis-Diiodoethylene; (Z)-1,2-Diiodoethene; (Z)-1,2-Diiodoethylene; (1Z)-1,2-Diiodoethene; (1Z)-1,2-Diiodoethylene; c-CHICHI; c-C2H2I2; Acetylene diiodide; CHICHI

Relative Molecular Mass: 279.8462 ± 0.0016

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
217.44	209.16	± 0.35	kJ/mol

3D Image of CHICHI (g, cis)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CHICHI (g, cis)

The 10 contributors listed below account for 90.1% of the provenance of Δ_fH° of CHICHI (g, cis).

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.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
53.0	7564.1	CHICHI (g, cis) → HCCH (g) + I2 (g)	Δ_rG°(600 K) = 0.60 ± 0.10 kcal/mol	Furuyama 1968
23.8	7565.1	CHICHI (g, trans) → HCCH (g) + I2 (g)	Δ_rG°(600 K) = 1.26 ± 0.10 kcal/mol	Furuyama 1968
11.7	7566.1	CHICHI (g, cis) → CHICHI (g, trans)	Δ_rG°(548 K) = -0.58 ± 0.07 kcal/mol	Furuyama 1968
0.3	2375.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
0.2	2268.11	CO (g) → C (g) + O (g)	Δ_rH°(0 K) = 1071.92 ± 0.10 kJ/mol	Thorpe 2021
0.2	2286.9	C (graphite) + CO2 (g) → 2 CO (g)	Δ_rG°(1165 K) = -33.545 ± 0.058 kJ/mol	Smith 1946, note COf, 3rd Law
0.1	2596.7	HCCH (g) → 2 C (g) + 2 H (g)	Δ_rH°(0 K) = 1626.04 ± 0.56 kJ/mol	Harding 2008
0.1	2595.13	HCCH (g) → 2 C (g) + 2 H (g)	Δ_rH°(0 K) = 388.71 ± 0.15 kcal/mol	Karton 2007a
0.1	2310.7	HCCH (g) → 2 H (g) + C2 (g)	Δ_rH°(0 K) = 244.65 ± 0.15 kcal/mol	Karton 2007a
0.1	125.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CHICHI (g, cis)

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.

Correlation Coefficent (%)	Species Name	Formula	Image	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
70.8	trans-1,2-Diiodoethene	CHICHI (g, trans)	$C(\I)=C/I$	215.10	207.70	± 0.35	kJ/mol	279.8462 ± 0.0016	590-27-2*0
33.6	Acetylene	HCCH (g)		228.86	228.30	± 0.12	kJ/mol	26.0373 ± 0.0016	74-86-2*0
33.6	Acetylene cation	[HCCH]+ (g)		1328.88	1328.21	± 0.12	kJ/mol	26.0367 ± 0.0016	25641-79-6*0
26.4	Ethynylium	[CCH]+ (g)		1687.62	1690.95	± 0.15	kJ/mol	25.0288 ± 0.0016	16456-59-0*0
21.7	Ethynyl	CCH (g)		563.73	567.85	± 0.15	kJ/mol	25.0293 ± 0.0016	2122-48-7*0
18.6	Carbon cation	C+ (g)		1797.834	1803.432	± 0.039	kJ/mol	12.01015 ± 0.00080	14067-05-1*0
18.6	Carbon	C (g, triplet)		711.381	716.866	± 0.039	kJ/mol	12.01070 ± 0.00080	7440-44-0*1
18.6	Carbon	C (g)		711.381	716.866	± 0.039	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
18.6	Carbon	C (g, singlet)		833.312	838.459	± 0.039	kJ/mol	12.01070 ± 0.00080	7440-44-0*2
18.6	Carbon	C (g, quintuplet)		1114.944	1120.091	± 0.039	kJ/mol	12.01070 ± 0.00080	7440-44-0*3

Most Influential reactions involving CHICHI (g, cis)

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

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
0.803	7566.1	CHICHI (g, cis) → CHICHI (g, trans)	Δ_rG°(548 K) = -0.58 ± 0.07 kcal/mol	Furuyama 1968
0.598	7564.1	CHICHI (g, cis) → HCCH (g) + I2 (g)	Δ_rG°(600 K) = 0.60 ± 0.10 kcal/mol	Furuyama 1968

References

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 21^st 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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument, Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
5		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]
6		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

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

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[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. http://www.jmol.org/.

Acknowledgement

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.