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].
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Dibromine |
Formula: Br2 (g) |
CAS RN: 7726-95-6 |
ATcT ID: 7726-95-6*0 |
SMILES: BrBr |
InChI: InChI=1S/Br2/c1-2 |
InChIKey: GDTBXPJZTBHREO-UHFFFAOYSA-N |
Hills Formula: Br2 |
2D Image: |
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Aliases: Br2; Dibromine; Bromine molecule; Bromine; Molecular bromine; Diatomic bromine; UN 1744 |
Relative Molecular Mass: 159.8080 ± 0.0020 |
ΔfH°(0 K) | ΔfH°(298.15 K) | Uncertainty | Units |
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45.70 | 30.90 | ± 0.11 | kJ/mol |
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3D Image of Br2 (g) |
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spin ON spin OFF |
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Top contributors to the provenance of ΔfH° of Br2 (g)The 1 contributors listed below account for 93.0% of the provenance of ΔfH° of Br2 (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.
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Top 10 species with enthalpies of formation correlated to the ΔfH° of Br2 (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.
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Correlation Coefficent (%) | Species Name | Formula | Image | ΔfH°(0 K) | ΔfH°(298.15 K) | Uncertainty | Units | Relative Molecular Mass | ATcT ID | 100.0 | Bromine atom | Br (g) | | 117.925 | 111.863 | ± 0.055 | kJ/mol | 79.90400 ± 0.00100 | 10097-32-2*0 | 100.0 | Bromine atom | Br (g, 2P3/2) | | 117.925 | 111.863 | ± 0.055 | kJ/mol | 79.90400 ± 0.00100 | 10097-32-2*1 | 100.0 | Bromine atom | Br (g, 2P1/2) | | 162.010 | 155.947 | ± 0.055 | kJ/mol | 79.90400 ± 0.00100 | 10097-32-2*2 | 100.0 | Bromide | Br- (g) | | -206.612 | -212.674 | ± 0.055 | kJ/mol | 79.90455 ± 0.00100 | 24959-67-9*0 | 99.4 | Bromanylium | Br+ (g) | | 1257.786 | 1251.723 | ± 0.056 | kJ/mol | 79.90345 ± 0.00100 | 22541-56-6*0 | 93.5 | Bromochlorane | BrCl (g) | | 21.891 | 14.447 | ± 0.059 | kJ/mol | 115.3567 ± 0.0013 | 13863-41-7*0 | 83.1 | Iodine monobromide | IBr (g) | | 49.727 | 40.780 | ± 0.066 | kJ/mol | 206.8085 ± 0.0010 | 7789-33-5*0 | 48.5 | Diatomic bromine cation | [Br2]+ (g) | | 1060.34 | 1045.39 | ± 0.23 | kJ/mol | 159.8075 ± 0.0020 | 12595-71-0*0 | 35.9 | Hydrogen bromide | HBr (g) | | -27.52 | -35.36 | ± 0.12 | kJ/mol | 80.9119 ± 0.0010 | 10035-10-6*0 | 35.9 | Bromoniumyl | [HBr]+ (g) | | 1098.16 | 1090.31 | ± 0.12 | kJ/mol | 80.9114 ± 0.0010 | 12258-64-9*0 |
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Most Influential reactions involving Br2 (g)Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.
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Influence Coefficient | TN ID | Reaction | Measured Quantity | Reference | 0.996 | 7597.1 | Br2 (g) + CH2F2 (g) → HBr (g) + CHF2Br (g)  | ΔrH°(298.15 K) = -9.54 ± 0.07 kcal/mol | Okafo 1974, as quoted by Cox 1970 | 0.930 | 1108.2 | Br2 (cr,l) → Br2 (g)  | ΔrH°(298.15 K) = 7.386 ± 0.027 kcal/mol | Hildenbrand 1958 | 0.897 | 6797.3 | CO (g) + Br2 (g) → CBr2O (g)  | ΔrG°(444 K) = 6.169 ± 0.088 kcal/mol | Dunning 1972, 3rd Law | 0.821 | 1109.13 | Br2 (g) → 2 Br (g)  | ΔrH°(0 K) = 15895.537 ± 0.020 cm-1 | Gerstenkorn 1989, Br 79.90 | 0.802 | 6368.1 | Br2 (g) + CHCl3 (g) → HBr (g) + CCl3Br (g)  | ΔrH°(298.15 K) = -1.41 ± 0.10 kcal/mol | Mendenhall 1973, as quoted by Pedley 1986 | 0.789 | 6579.2 | CF3CF3 (g) + Br2 (g) → 2 CF3Br (g)  | ΔrG°(670.8 K) = -1.58 ± 0.62 kJ/mol | Coomber 1967a, 3rd Law | 0.762 | 7627.1 | CH2CH2 (g) + Br2 (g) → CH2BrCH2Br (g)  | ΔrH°(355 K) = -29.058 ± 0.300 kcal/mol | Conn 1938 | 0.706 | 1222.6 | 2 BrCl (g) → Br2 (g) + Cl2 (g)  | ΔrG°(295.15 K) = 5.419 ± 0.049 kJ/mol | Tellinghuisen 2003, 3rd Law | 0.586 | 1123.1 | Br- (g) + Br2 (g) → [Br2]- (g) + Br (g)  | ΔrH°(0 K) = 0.84 ± 0.03 eV | Chupka 1971b | 0.458 | 1111.1 | Br2 (g) → [Br2]+ (g)  | ΔrH°(0 K) = 10.518 ± 0.003 eV | Yencha 1995 | 0.302 | 6373.1 | CHBr3 (g) + Br2 (g) → CBr4 (g) + HBr (g)  | ΔrG°(588.3 K) = 3.27 ± 1.00 kJ/mol | King 1971, 3rd Law | 0.289 | 1206.4 | [Br3]- (g) → Br- (g) + Br2 (g)  | ΔrH°(298.15 K) = 30.6 ± 0.8 kcal/mol | Thanthiriwatte 2014, est unc | 0.246 | 1293.1 | I- (g) + Br2 (g) → [Br2]- (g) + I (g)  | ΔrH°(0 K) = 0.59 ± 0.03 (×1.542) eV | Chupka 1971b | 0.202 | 1205.1 | Br3 (g) → Br2 (g) + Br (g)  | ΔrH°(0 K) = 13 ± 7 kJ/mol | Kawasaki 1989 | 0.183 | 6018.1 | CCl3 (g) + Br2 (g) → CCl3Br (g) + Br (g)  | ΔrG°(437 K) = -3.5 ± 0.5 kcal/mol | Hudgens 1991, 3rd Law | 0.165 | 1111.7 | Br2 (g) → [Br2]+ (g)  | ΔrH°(0 K) = 10.516 ± 0.005 eV | Ruscic 1994 | 0.165 | 1111.2 | Br2 (g) → [Br2]+ (g)  | ΔrH°(0 K) = 10.515 ± 0.005 eV | van Lonkhuyzen 1984 | 0.137 | 6367.1 | Br2 (g) + CCl4 (g) → BrCl (g) + CCl3Br (g)  | ΔrH°(298.15 K) = 8.84 ± 0.30 kcal/mol | Mendenhall 1973, as quoted by Pedley 1986 | 0.117 | 1220.9 | 2 BrCl (g) → Br2 (g) + Cl2 (g)  | ΔrG°(301.15 K) = 5.54 ± 0.12 kJ/mol | Vesper 1934, 3rd Law, est unc | 0.109 | 6344.1 | CF3Cl (g) + Br2 (g) → CF3Br (g) + BrCl (g)  | ΔrH°(298.15 K) = 10.49 ± 0.40 (×1.044) kcal/mol | Coomber 1967b, as quoted by Cox 1970 |
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References
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1
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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]
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2
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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]
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3
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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
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T. L. Nguyen et al, ongoing studies (2024)
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5
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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]
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6
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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]
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Formula
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The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.
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Uncertainties
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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.
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Website Functionality Credits
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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/.
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Acknowledgement
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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.
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