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].

Difluoromethane

Formula: CH2F2 (l)
CAS RN: 75-10-5
ATcT ID: 75-10-5*590
SMILES: C(F)F
InChI: InChI=1S/CH2F2/c2-1-3/h1H2
InChIKey: RWRIWBAIICGTTQ-UHFFFAOYSA-N
Hills Formula: C1H2F2

2D Image:

C(F)F
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

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
-468.92± 0.37kJ/mol

Top contributors to the provenance of ΔfH° of CH2F2 (l)

The 20 contributors listed below account only for 65.4% of the provenance of ΔfH° of CH2F2 (l).
A total of 82 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
8.56356.3 CH2F2 (l) → CH2F2 (g) ΔrH°(245 K) = 20.48 ± 0.15 kJ/molKanungo 1987, 2nd Law
6.46348.3 CH2F2 (g) → C (g) + 2 H (g) + 2 F (g) ΔrH°(0 K) = 416.24 ± 0.3 kcal/molFeller 2008
6.46347.11 CH2F2 (g) → C (g) + 2 H (g) + 2 F (g) ΔrH°(0 K) = 416.01 ± 0.30 kcal/molSylvetsky 2016, Karton 2011
5.76427.7 CF4 (g) CH4 (g) → 2 CH2F2 (g) ΔrH°(0 K) = 107.8 ± 2.5 kJ/molKlopper 2010a, est unc
5.47558.1 CH2F2 (g) O2 (g) → CO2 (g) + 2 HF (aq, 23 H2O) ΔrH°(298.15 K) = -139.80 ± 0.22 (×1.445) kcal/molNeugebauer 1958, Paulechka 2019
5.26354.6 CH2F2 (g) → CH3F (g) CHF3 (g) ΔrH°(0 K) = -31.06 ± 2.0 kJ/molCsontos 2010
3.36356.2 CH2F2 (l) → CH2F2 (g) ΔrH°(221.6 K) = 21.83 ± 0.24 kJ/molKanungo 1987, 2nd Law
3.36354.7 CH2F2 (g) → CH3F (g) CHF3 (g) ΔrH°(0 K) = -29.9 ± 2.5 kJ/molKlopper 2010a, est unc
2.56349.1 CH2F2 (g) → C (g) H2 (g) F2 (g) ΔrH°(0 K) = 1154.24 ± 2.0 kJ/molCsontos 2010
2.56427.6 CF4 (g) CH4 (g) → 2 CH2F2 (g) ΔrH°(0 K) = 25.56 ± 0.9 kcal/molRuscic W1RO
2.06428.7 CH3F (g) CF4 (g) → CH2F2 (g) CHF3 (g) ΔrH°(0 K) = 22.4 ± 2.5 kJ/molKlopper 2010a, est unc
2.06427.4 CF4 (g) CH4 (g) → 2 CH2F2 (g) ΔrH°(0 K) = 25.58 ± 1.0 kcal/molRuscic G4
2.06352.6 CH2F2 (g) + 2 F (g) → CF4 (g) + 2 H (g) ΔrH°(0 K) = -207.81 ± 2.0 kJ/molCsontos 2010
1.76353.6 CH2F2 (g) H (g) → CH3F (g) F (g) ΔrH°(0 K) = 75.39 ± 2.0 kJ/molCsontos 2010
1.76427.3 CF4 (g) CH4 (g) → 2 CH2F2 (g) ΔrH°(0 K) = 25.47 ± 1.1 kcal/molRuscic G3X
1.46354.5 CH2F2 (g) → CH3F (g) CHF3 (g) ΔrH°(0 K) = -7.33 ± 0.9 kcal/molRuscic W1RO
1.26427.5 CF4 (g) CH4 (g) → 2 CH2F2 (g) ΔrH°(0 K) = 24.82 ± 1.3 kcal/molRuscic CBS-n
1.16354.4 CH2F2 (g) → CH3F (g) CHF3 (g) ΔrH°(0 K) = -7.57 ± 1.0 kcal/molRuscic CBS-n
1.16354.2 CH2F2 (g) → CH3F (g) CHF3 (g) ΔrH°(0 K) = -7.25 ± 1.0 kcal/molRuscic G4
1.16353.7 CH2F2 (g) H (g) → CH3F (g) F (g) ΔrH°(0 K) = 79.0 ± 2.5 kJ/molKlopper 2010a, est unc

Top 10 species with enthalpies of formation correlated to the ΔfH° of CH2F2 (l)

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    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
93.8 DifluoromethaneCH2F2 (g)C(F)F-443.33-450.94± 0.35kJ/mol52.02339 ±
0.00081
75-10-5*0
68.6 DifluorobromomethaneCHF2Br (g)C(F)(F)Br-411.40-424.60± 0.47kJ/mol130.9194 ±
0.0013
1511-62-2*0
33.9 FluoroformCHF3 (g)C(F)(F)F-689.29-696.24± 0.40kJ/mol70.01385 ±
0.00080
75-46-7*0
31.9 FluoroformCHF3 (l)C(F)(F)F-704.71± 0.42kJ/mol70.01385 ±
0.00080
75-46-7*590
23.5 FluoromethaneCH3F (g)CF-227.45-235.48± 0.24kJ/mol34.03292 ±
0.00083
593-53-3*0
18.1 TetrafluoromethaneCF4 (g)C(F)(F)(F)F-927.65-933.61± 0.23kJ/mol88.00431 ±
0.00080
75-73-0*0
14.9 PolytetrafluoroethyleneCF2CF2 (s)FC(C(F)(F)[*:1])(F)[*:2]-829.96± 0.54kJ/mol100.0150 ±
0.0016
9002-84-0*591
12.2 FluoromethaneCH3F (l)CF-245.75± 0.45kJ/mol34.03292 ±
0.00083
593-53-3*590
10.9 BromotrifluoromethaneCF3Br (g)FC(F)(F)Br-638.64-650.76± 0.39kJ/mol148.9099 ±
0.0013
75-63-8*0
10.2 IodotrifluoromethaneCF3I (g)C(F)(F)(F)I-583.20-589.11± 0.45kJ/mol195.91038 ±
0.00080
2314-97-8*0

Most Influential reactions involving CH2F2 (l)

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
0.7156356.3 CH2F2 (l) → CH2F2 (g) ΔrH°(245 K) = 20.48 ± 0.15 kJ/molKanungo 1987, 2nd Law
0.2796356.2 CH2F2 (l) → CH2F2 (g) ΔrH°(221.6 K) = 21.83 ± 0.24 kJ/molKanungo 1987, 2nd Law
0.0056356.1 CH2F2 (l) → CH2F2 (g) ΔrH°(221.43 K) = 19.89 ± 0.14 (×12.34) kJ/molThermoData 2004


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 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. 1.172 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.