Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Difluoromethane

Formula: CH2F2 (g)

CAS RN: 75-10-5

ATcT ID: 75-10-5*0

SMILES: C(F)F

InChI: InChI=1S/CH2F2/c2-1-3/h1H2

InChIKey: RWRIWBAIICGTTQ-UHFFFAOYSA-N

Hills Formula: C1H2F2

2D Image:

Aliases: CH2F2; Difluoromethane; Methylene fluoride; Methylene difluoride; Methane difluoride; Carbon difluoride; Difluorocarbon; FC 32; HFC 32; Freon 32; Genetron 32; R 32

Relative Molecular Mass: 52.02339 ± 0.00081

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-443.31	-450.93	± 0.33	kJ/mol

3D Image of CH2F2 (g)

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Top contributors to the provenance of Δ_fH° of CH2F2 (g)

The 20 contributors listed below account only for 63.7% of the provenance of Δ_fH° of CH2F2 (g).
A total of 90 contributors would be needed to account for 90% of the provenance.

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
9.1	6259.7	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 107.8 ± 2.0 kJ/mol	Klopper 2010a, est unc
6.6	6180.3	CH2F2 (g) → C (g) + 2 H (g) + 2 F (g)	Δ_rH°(0 K) = 416.24 ± 0.3 kcal/mol	Feller 2008
6.6	6179.11	CH2F2 (g) → C (g) + 2 H (g) + 2 F (g)	Δ_rH°(0 K) = 416.01 ± 0.30 kcal/mol	Sylvetsky 2016, Karton 2011
5.3	7285.1	CH2F2 (g) + O2 (g) → CO2 (g) + 2 HF (aq, 23 H2O)	Δ_rH°(298.15 K) = -139.80 ± 0.22 (×1.477) kcal/mol	Neugebauer 1958, Paulechka 2019
5.1	6186.6	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -31.06 ± 2.0 kJ/mol	Csontos 2010
5.1	6186.7	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -29.9 ± 2.0 kJ/mol	Klopper 2010a, est unc
3.3	6260.7	CH3F (g) + CF4 (g) → CH2F2 (g) + CHF3 (g)	Δ_rH°(0 K) = 22.4 ± 2.0 kJ/mol	Klopper 2010a, est unc
2.6	6181.1	CH2F2 (g) → C (g) + H2 (g) + F2 (g)	Δ_rH°(0 K) = 1154.24 ± 2.0 kJ/mol	Csontos 2010
2.5	6259.6	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 25.56 ± 0.9 kcal/mol	Ruscic W1RO
2.0	6259.4	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 25.58 ± 1.0 kcal/mol	Ruscic G4
1.9	6184.6	CH2F2 (g) + 2 F (g) → CF4 (g) + 2 H (g)	Δ_rH°(0 K) = -207.81 ± 2.0 kJ/mol	Csontos 2010
1.8	6185.7	CH2F2 (g) + H (g) → CH3F (g) + F (g)	Δ_rH°(0 K) = 79.0 ± 2.0 kJ/mol	Klopper 2010a, est unc
1.8	6185.6	CH2F2 (g) + H (g) → CH3F (g) + F (g)	Δ_rH°(0 K) = 75.39 ± 2.0 kJ/mol	Csontos 2010
1.7	6259.3	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 25.47 ± 1.1 kcal/mol	Ruscic G3X
1.4	6186.5	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -7.33 ± 0.9 kcal/mol	Ruscic W1RO
1.4	6258.9	CHF3 (g) + CH4 (g) → CH2F2 (g) + CH3F (g)	Δ_rH°(0 K) = 85.4 ± 2.0 kJ/mol	Klopper 2010a, est unc
1.3	6180.4	CH2F2 (g) → C (g) + 2 H (g) + 2 F (g)	Δ_rH°(0 K) = 1742.3 ± 2.8 kJ/mol	Klopper 2010a
1.2	6259.5	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 24.82 ± 1.3 kcal/mol	Ruscic CBS-n
1.1	6186.4	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -7.57 ± 1.0 kcal/mol	Ruscic CBS-n
1.1	6186.2	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -7.25 ± 1.0 kcal/mol	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH2F2 (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
93.2	Difluoromethane	CH2F2 (l)		-468.91	± 0.36	kJ/mol	52.02339 ± 0.00081	75-10-5*590
71.4	Difluorobromomethane	CHF2Br (g)	-411.39	-424.59	± 0.46	kJ/mol	130.9194 ± 0.0013	1511-62-2*0
38.1	Fluoroform	CHF3 (g)	-689.28	-696.23	± 0.38	kJ/mol	70.01385 ± 0.00080	75-46-7*0
35.8	Fluoroform	CHF3 (l)		-704.69	± 0.41	kJ/mol	70.01385 ± 0.00080	75-46-7*590
26.4	Fluoromethane	CH3F (g)	-227.42	-235.44	± 0.23	kJ/mol	34.03292 ± 0.00083	593-53-3*0
21.5	Tetrafluoromethane	CF4 (g)	-927.65	-933.62	± 0.23	kJ/mol	88.00431 ± 0.00080	75-73-0*0
17.8	Polytetrafluoroethylene	CF2CF2 (s)		-829.97	± 0.54	kJ/mol	100.0150 ± 0.0016	9002-84-0*591
13.2	Fluoromethane	CH3F (l)		-245.72	± 0.45	kJ/mol	34.03292 ± 0.00083	593-53-3*590
11.9	Bromotrifluoromethane	CF3Br (g)	-638.68	-650.80	± 0.40	kJ/mol	148.9099 ± 0.0013	75-63-8*0
11.1	Iodotrifluoromethane	CF3I (g)	-583.27	-589.15	± 0.45	kJ/mol	195.91038 ± 0.00080	2314-97-8*0

Most Influential reactions involving CH2F2 (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
0.996	7286.1	Br2 (g) + CH2F2 (g) → HBr (g) + CHF2Br (g)	Δ_rH°(298.15 K) = -9.54 ± 0.07 kcal/mol	Okafo 1974, as quoted by Cox 1970
0.715	6188.3	CH2F2 (l) → CH2F2 (g)	Δ_rH°(245 K) = 20.48 ± 0.15 kJ/mol	Kanungo 1987, 2nd Law
0.279	6188.2	CH2F2 (l) → CH2F2 (g)	Δ_rH°(221.6 K) = 21.83 ± 0.24 kJ/mol	Kanungo 1987, 2nd Law
0.119	6261.7	CH2F2 (g) + CF4 (g) → 2 CHF3 (g)	Δ_rH°(0 K) = -7.5 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.104	6259.7	CF4 (g) + CH4 (g) → 2 CH2F2 (g)	Δ_rH°(0 K) = 107.8 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.096	6186.6	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -31.06 ± 2.0 kJ/mol	Csontos 2010
0.096	6186.7	2 CH2F2 (g) → CH3F (g) + CHF3 (g)	Δ_rH°(0 K) = -29.9 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.081	6222.4	CH2FCl (g) + F (g) → CH2F2 (g) + Cl (g)	Δ_rH°(0 K) = -143.01 ± 3.1 kJ/mol	Csontos 2010
0.078	7285.1	CH2F2 (g) + O2 (g) → CO2 (g) + 2 HF (aq, 23 H2O)	Δ_rH°(298.15 K) = -139.80 ± 0.22 (×1.477) kcal/mol	Neugebauer 1958, Paulechka 2019
0.078	6260.7	CH3F (g) + CF4 (g) → CH2F2 (g) + CHF3 (g)	Δ_rH°(0 K) = 22.4 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.067	6180.3	CH2F2 (g) → C (g) + 2 H (g) + 2 F (g)	Δ_rH°(0 K) = 416.24 ± 0.3 kcal/mol	Feller 2008
0.067	6179.11	CH2F2 (g) → C (g) + 2 H (g) + 2 F (g)	Δ_rH°(0 K) = 416.01 ± 0.30 kcal/mol	Sylvetsky 2016, Karton 2011
0.056	6187.9	CH2F2 (g) + CH4 (g) → 2 CH3F (g)	Δ_rH°(0 K) = 55.5 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.052	6258.9	CHF3 (g) + CH4 (g) → CH2F2 (g) + CH3F (g)	Δ_rH°(0 K) = 85.4 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.039	6183.6	CH2F2 (g) + F (g) → CHF3 (g) + H (g)	Δ_rH°(0 K) = -106.45 ± 2.0 kJ/mol	Csontos 2010
0.039	6183.7	CH2F2 (g) + F (g) → CHF3 (g) + H (g)	Δ_rH°(0 K) = -108.9 ± 2.0 kJ/mol	Klopper 2010a, est unc
0.033	6261.6	CH2F2 (g) + CF4 (g) → 2 CHF3 (g)	Δ_rH°(0 K) = -2.05 ± 0.9 kcal/mol	Ruscic W1RO
0.031	6184.6	CH2F2 (g) + 2 F (g) → CF4 (g) + 2 H (g)	Δ_rH°(0 K) = -207.81 ± 2.0 kJ/mol	Csontos 2010
0.031	6222.3	CH2FCl (g) + F (g) → CH2F2 (g) + Cl (g)	Δ_rH°(0 K) = -34.79 ± 1.2 kcal/mol	Ruscic W1RO
0.029	6185.6	CH2F2 (g) + H (g) → CH3F (g) + F (g)	Δ_rH°(0 K) = 75.39 ± 2.0 kJ/mol	Csontos 2010

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. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
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.