Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Dibromomethane

Formula: CH2Br2 (g)
CAS RN: 74-95-3
ATcT ID: 74-95-3*0
SMILES: C(Br)Br
InChI: InChI=1S/CH2Br2/c2-1-3/h1H2
InChIKey: FJBFPHVGVWTDIP-UHFFFAOYSA-N
Hills Formula: C1H2Br2

2D Image:

C(Br)Br
Aliases: CH2Br2; Dibromomethane; Methylene bromide; Methylene dibromide; Methane dibromide; Carbon dibromide; Dibromocarbon; RCRA U068; UN 2664
Relative Molecular Mass: 173.8346 ± 0.0022

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
27.035.62± 0.64kJ/mol

3D Image of CH2Br2 (g)

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Top contributors to the provenance of ΔfH° of CH2Br2 (g)

The 20 contributors listed below account only for 69.8% of the provenance of ΔfH° of CH2Br2 (g).
A total of 45 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
13.46476.6 CH4 (g) CBr4 (g) → 2 CH2Br2 (g) ΔrH°(0 K) = -24.6 ± 2.5 kJ/molBross 2023
6.16405.8 CH2Br2 (g) → C (g) + 2 H (g) + 2 Br (g) ΔrH°(0 K) = 1352.2 ± 2.5 kJ/molBross 2023
5.56407.2 CH2Br2 (g) + 2 H2 (g) → CH4 (g) + 2 HBr (g) ΔrH°(0 K) = -148.5 ± 2.5 kJ/molBross 2023
5.36478.6 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -17.1 ± 2.5 kJ/molBross 2023
5.06408.2 CH2Br2 (g) H2 (g) → CH3Br (g) HBr (g) ΔrH°(0 K) = -74.8 ± 2.5 kJ/molBross 2023
4.56411.2 CH2Br2 (g) CH4 (g) → 2 CH3Br (g) ΔrH°(0 K) = -1.1 ± 2.5 kJ/molBross 2023
4.56474.7 CH4 (g) CH2Br2 (g) → 2 CH3Br (g) ΔrH°(0 K) = -1.1 ± 2.5 kJ/molBross 2023
3.06406.1 CH2Br2 (g) + 2 Cl (g) → CH2Cl2 (g) + 2 Br (g) ΔrH°(0 K) = -1.209 ± 0.035 eVLago 2005
2.66435.1 CH2ClBr (g) Br (g) → CH2Br2 (g) Cl (g) ΔrH°(0 K) = 0.583 ± 0.032 eVLago 2005
2.36413.2 CH2Br2 (g) + 2 CH3Br (g) → CBr4 (g) + 2 CH4 (g) ΔrH°(0 K) = 25.7 ± 2.5 kJ/molBross 2023
2.01108.2 Br2 (cr,l) → Br2 (g) ΔrH°(298.15 K) = 7.386 ± 0.027 kcal/molHildenbrand 1958
1.86412.2 CH2Br2 (g) CH3Br (g) → CHBr3 (g) CH4 (g) ΔrH°(0 K) = 7.5 ± 2.5 kJ/molBross 2023
1.86475.6 CH4 (g) CHBr3 (g) → CH2Br2 (g) CH3Br (g) ΔrH°(0 K) = -7.5 ± 2.5 kJ/molBross 2023
1.76410.2 CH2Br2 (g) + 2 HBr (g) → CBr4 (g) + 2 H2 (g) ΔrH°(0 K) = 173.1 ± 2.5 kJ/molBross 2023
1.66474.4 CH4 (g) CH2Br2 (g) → 2 CH3Br (g) ΔrH°(0 K) = 0.28 ± 1.0 kcal/molRuscic G4
1.66409.2 CH2Br2 (g) HBr (g) → CHBr3 (g) H2 (g) ΔrH°(0 K) = 81.2 ± 2.5 kJ/molBross 2023
1.66235.8 CBr4 (g) → C (g) + 4 Br (g) ΔrH°(0 K) = 1037.9 ± 2.5 kJ/molBross 2023
1.56369.7 CHBr3 (g) → C (g) H (g) + 3 Br (g) ΔrH°(0 K) = 1200.4 ± 2.5 kJ/molBross 2023
1.56236.6 CBr4 (g) + 4 H (g) → CH4 (g) + 4 Br (g) ΔrH°(0 K) = -604.0 ± 2.5 kJ/molBross 2023
1.56478.4 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -2.81 ± 1.0 (×1.091) kcal/molRuscic G4

Top 10 species with enthalpies of formation correlated to the ΔfH° of CH2Br2 (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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
48.3 BromoformCHBr3 (g)C(Br)(Br)Br80.9254.77± 0.71kJ/mol252.7306 ±
0.0031
75-25-2*0
47.8 BromoformCHBr3 (l)C(Br)(Br)Br8.73± 0.72kJ/mol252.7306 ±
0.0031
75-25-2*590
47.5 TetrabromomethaneCBr4 (g)BrC(Br)(Br)Br144.72115.02± 0.74kJ/mol331.6267 ±
0.0041
558-13-4*0
36.6 TetrabromomethaneCBr4 (cr, monoclinic)BrC(Br)(Br)Br60.54± 0.96kJ/mol331.6267 ±
0.0041
558-13-4*500
27.5 BromomethaneCH3Br (g)CBr-20.48-35.88± 0.19kJ/mol94.9385 ±
0.0013
74-83-9*0
26.7 Bromomethane cation[CH3Br]+ (g)C[Br+]996.63981.72± 0.20kJ/mol94.9380 ±
0.0013
12538-70-4*0
26.1 BromomethaneCH3Br (l)CBr-56.20-59.22± 0.20kJ/mol94.9385 ±
0.0013
74-83-9*590
20.5 Hydrogen bromideHBr (g)Br-27.52-35.36± 0.12kJ/mol80.9119 ±
0.0010
10035-10-6*0
20.5 Bromoniumyl[HBr]+ (g)[BrH+]1098.161090.31± 0.12kJ/mol80.9114 ±
0.0010
12258-64-9*0
18.9 TribromochloromethaneCBr3Cl (g)ClC(Br)(Br)Br86.763.8± 1.4kJ/mol287.1754 ±
0.0032
594-15-0*0

Most Influential reactions involving CH2Br2 (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
0.2026476.6 CH4 (g) CBr4 (g) → 2 CH2Br2 (g) ΔrH°(0 K) = -24.6 ± 2.5 kJ/molBross 2023
0.1856435.1 CH2ClBr (g) Br (g) → CH2Br2 (g) Cl (g) ΔrH°(0 K) = 0.583 ± 0.032 eVLago 2005
0.1646479.6 CH2Br2 (g) CBr4 (g) → 2 CHBr3 (g) ΔrH°(0 K) = -10.7 ± 2.5 kJ/molBross 2023
0.1076478.6 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -17.1 ± 2.5 kJ/molBross 2023
0.0866413.2 CH2Br2 (g) + 2 CH3Br (g) → CBr4 (g) + 2 CH4 (g) ΔrH°(0 K) = 25.7 ± 2.5 kJ/molBross 2023
0.0796410.2 CH2Br2 (g) + 2 HBr (g) → CBr4 (g) + 2 H2 (g) ΔrH°(0 K) = 173.1 ± 2.5 kJ/molBross 2023
0.0746412.2 CH2Br2 (g) CH3Br (g) → CHBr3 (g) CH4 (g) ΔrH°(0 K) = 7.5 ± 2.5 kJ/molBross 2023
0.0746475.6 CH4 (g) CHBr3 (g) → CH2Br2 (g) CH3Br (g) ΔrH°(0 K) = -7.5 ± 2.5 kJ/molBross 2023
0.0736409.2 CH2Br2 (g) HBr (g) → CHBr3 (g) H2 (g) ΔrH°(0 K) = 81.2 ± 2.5 kJ/molBross 2023
0.0656474.7 CH4 (g) CH2Br2 (g) → 2 CH3Br (g) ΔrH°(0 K) = -1.1 ± 2.5 kJ/molBross 2023
0.0656411.2 CH2Br2 (g) CH4 (g) → 2 CH3Br (g) ΔrH°(0 K) = -1.1 ± 2.5 kJ/molBross 2023
0.0636405.8 CH2Br2 (g) → C (g) + 2 H (g) + 2 Br (g) ΔrH°(0 K) = 1352.2 ± 2.5 kJ/molBross 2023
0.0636407.2 CH2Br2 (g) + 2 H2 (g) → CH4 (g) + 2 HBr (g) ΔrH°(0 K) = -148.5 ± 2.5 kJ/molBross 2023
0.0606408.2 CH2Br2 (g) H2 (g) → CH3Br (g) HBr (g) ΔrH°(0 K) = -74.8 ± 2.5 kJ/molBross 2023
0.0586479.4 CH2Br2 (g) CBr4 (g) → 2 CHBr3 (g) ΔrH°(0 K) = -2.00 ± 1.0 kcal/molRuscic G4
0.0486479.3 CH2Br2 (g) CBr4 (g) → 2 CHBr3 (g) ΔrH°(0 K) = -2.21 ± 1.1 kcal/molRuscic G3X
0.0406406.1 CH2Br2 (g) + 2 Cl (g) → CH2Cl2 (g) + 2 Br (g) ΔrH°(0 K) = -1.209 ± 0.035 eVLago 2005
0.0326478.4 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -2.81 ± 1.0 (×1.091) kcal/molRuscic G4
0.0316478.3 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -2.99 ± 1.1 kcal/molRuscic G3X
0.0236474.4 CH4 (g) CH2Br2 (g) → 2 CH3Br (g) ΔrH°(0 K) = 0.28 ± 1.0 kcal/molRuscic G4


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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   T. L. Nguyen et al, ongoing studies (2024)
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.