Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Chlorine atom

Formula: Cl (g)

CAS RN: 22537-15-1

ATcT ID: 22537-15-1*0

SMILES: [Cl]

InChI: InChI=1S/Cl

InChIKey: ZAMOUSCENKQFHK-UHFFFAOYSA-N

Hills Formula: Cl1

2D Image:

Aliases: Cl; Chlorine atom; Chlorine; Chloranyl; Atomic chlorine; Chlorine radical; Chloro radical; Monochlorine; Cl-atom

Relative Molecular Mass: 35.45270 ± 0.00090

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
119.621	121.302	± 0.0011	kJ/mol

3D Image of Cl (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of Cl (g)

The 2 contributors listed below account for 97.0% of the provenance of Δ_fH° of Cl (g).

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
67.1	741.7	Cl2 (g) → 2 Cl (g)	Δ_rH°(0 K) = 19999.12 ± 0.2 cm-1	Douglas 1975, est unc
29.8	741.6	Cl2 (g) → 2 Cl (g)	Δ_rH°(0 K) = 19999.09 ± 0.3 cm-1	LeRoy 1971, note Cl2, LeRoy 1970d, LeRoy 1970b

Top 10 species with enthalpies of formation correlated to the Δ_fH° of Cl (g)

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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
99.9	Chlorine atom	Cl (g, 2P3/2)	119.621	121.228	± 0.0011	kJ/mol	35.45270 ± 0.00090	22537-15-1*1
99.9	Chlorine atom	Cl (g, 2P1/2)	130.176	131.783	± 0.0011	kJ/mol	35.45270 ± 0.00090	22537-15-1*2
60.3	Chlorine atom cation	Cl+ (g)	1370.807	1372.603	± 0.0021	kJ/mol	35.45215 ± 0.00090	24203-47-2*0
36.5	Chloride	Cl- (g)	-228.953	-227.346	± 0.0021	kJ/mol	35.45325 ± 0.00090	16887-00-6*0
17.1	Chloroniumyl ion	[HCl]+ (g)	1137.798	1137.732	± 0.0051	kJ/mol	36.46009 ± 0.00090	12258-94-5*0
15.9	Hydrogen chloride	HCl (g)	-91.988	-92.172	± 0.0062	kJ/mol	36.46064 ± 0.00090	7647-01-0*0
8.1	Chlorine atom dication	[Cl]+2 (g)	3668.474	3670.081	± 0.013	kJ/mol	35.45160 ± 0.00090	15723-23-6*0
8.0	Iodine monochloride	ICl (g)	19.024	17.391	± 0.013	kJ/mol	162.35717 ± 0.00090	7790-99-0*0
4.2	Hypochlorous acid	HOCl (g)	-73.841	-76.781	± 0.024	kJ/mol	52.46004 ± 0.00095	7790-92-3*0
3.7	Hydrogen chloride	HCl (aq)		-166.989	± 0.023	kJ/mol	36.46064 ± 0.00090	7647-01-0*800

Most Influential reactions involving Cl (g)

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
1.000	957.4	[ClOO]+ (g) → 2 O (g) + Cl (g)	Δ_rH°(0 K) = -143.84 ± 1.50 kcal/mol	Ruscic W1RO
1.000	761.1	Cl (g) → Cl (g, 2P3/2)	Δ_rH°(0 K) = 0.00 ± 0.00 cm-1	triv
0.986	1349.1	ICl (g) → I (g) + Cl (g)	Δ_rH°(0 K) = 17367.0 ± 1.0 cm-1	Hulthen 1961, note ICl, Cl 35.45
0.928	882.1	[ClF]- (g) → Cl (g) + F- (g)	Δ_rH°(0 K) = 29.80 ± 0.2 kcal/mol	Vassilakis 2014, est unc
0.927	934.1	ClO (g) → Cl (g) + O (g)	Δ_rH°(0 K) = 22182.3 ± 3 cm-1	Coxon 1976, note ClO, note ClOa
0.911	6367.1	CHCl2Br (g) + Cl (g) → CHCl3 (g) + Br (g)	Δ_rH°(0 K) = -0.642 ± 0.012 eV	Shuman 2008a
0.804	6344.1	CH2ClBr (g) + Cl (g) → CH2Cl2 (g) + Br (g)	Δ_rH°(0 K) = -0.626 ± 0.014 eV	Lago 2005
0.798	6702.1	ClCO (g) → Cl (g) + CO (g)	Δ_rG°(222.5 K) = 2.32 ± 0.13 kcal/mol	Nicovich 1990a, 3rd Law
0.785	759.2	Cl- (g) → Cl (g)	Δ_rH°(0 K) = 29138.59 ± 0.22 cm-1	Berzinsh 1995
0.747	7070.1	C6H5C(O)Cl (g) → [C6H5CO]+ (g) + Cl (g)	Δ_rH°(0 K) = 10.09 ± 0.01 eV	Traeger 2009
0.729	1036.1	HOCl (g) → OH (g) + Cl (g)	Δ_rH°(0 K) = 19287.9 ± 0.7 cm-1	Barnes 1997
0.701	963.2	ClOO (g) → Cl (g) + O2 (g)	Δ_rG°(240 K) = -0.84 ± 0.40 kJ/mol	Baer 1991, 3rd Law, note unc
0.671	741.7	Cl2 (g) → 2 Cl (g)	Δ_rH°(0 K) = 19999.12 ± 0.2 cm-1	Douglas 1975, est unc
0.574	752.1	Cl (g) → Cl+ (g)	Δ_rH°(0 K) = 104591.01 ± 0.14 cm-1	Yang 2015, est unc
0.536	6371.4	CF2ClBr (g) → C (g) + 2 F (g) + Cl (g) + Br (g)	Δ_rH°(0 K) = 365.48 ± 1.60 kcal/mol	Ruscic G4
0.536	6373.4	CBr2FCl (g) → C (g) + 2 Br (g) + F (g) + Cl (g)	Δ_rH°(0 K) = 312.84 ± 1.60 kcal/mol	Ruscic G4
0.536	6370.4	CHFClBr (g) → C (g) + H (g) + F (g) + Cl (g) + Br (g)	Δ_rH°(0 K) = 348.46 ± 1.60 kcal/mol	Ruscic G4
0.536	6372.4	CCl2FBr (g) → C (g) + 2 Cl (g) + F (g) + Br (g)	Δ_rH°(0 K) = 327.67 ± 1.60 kcal/mol	Ruscic G4
0.497	1073.8	HOCl(O)O (g) → H (g) + Cl (g) + 3 O (g)	Δ_rH°(0 K) = 257.25 ± 0.35 kcal/mol	Karton 2017
0.475	764.2	Cl- (g) + Cl2 (g) → [Cl2]- (g) + Cl (g)	Δ_rH°(0 K) = 1.208 ± 0.005 eV	Feller 2016a, est unc

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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
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]
7		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 [6] and Ruscic and Bross[7]).
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.