Ab initio thermochemistry for unsaturated C sub 2 hydrocarbons

Journal Article · Thu Oct 17 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100174a058· OSTI ID:7017538

Wu, C J; Carter, E A ^[1]

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1. Univ. of California, Los Angeles (United States)

The first systematic study of the sequential bond dissociation energies for ethylene and acetylene, using generalized valence bond (GVB) theory and the correlation-consistent configuration interaction (CCCI) method is presented. The ab initio GVB/CCCI sequential C-H bond strengths in ethylene and acetylene are: D{sub 0}(H{sub 2}CCH-H) = 109.5 (110.9 {plus minus} 2) kcal/mol, D{sub 0}(H{sub 2}CC-H) = 70.8 (74.4 {plus minus} 3) kcal/mol, D{sub 0}(HCCH-H) = 37.1 (40.0 {plus minus} 3) kcal/mol, D{sub 0}(CCH-H) = 86.3 (91.3 {plus minus} 5) kcal/mol, D{sub 0}(HCC-H) = 129.7 (131.1 {plus minus} 2) kcal/mol, and D{sub 0}(CC-H) = 95.6 (102.5 {plus minus} 3) kcal/mol. The values in parentheses represent best estimates for the actual band strengths, taking into account known systematic and random errors. New predictions for C{double bond}C double bond strengths are D{sub 0}(H{sub 2}C{double bond}CH) = 162.5 (168.2 {plus minus} 6) kcal/mol and D{sub 0}(H{sub 2}C{double bond}C) = 149.5 (155.5 {plus minus} 5) kcal/mol, while predictions for C{triple bond}C triple bond strengths are: D{sub 0}(HC{triple bond}C) = 160.4 (168.9 {plus minus} 13) kcal/mol and D{sub 0}(C{triple bond}C) = 134.7 (129.2 {plus minus} 15) kcal/mol.

• OSTI ID: 7017538
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:21; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACETYLENE
ALKENES
ALKYNES
BINDING ENERGY
CHEMICAL BONDS
CONFIGURATION INTERACTION
DATA
ENERGY
ENERGY LEVELS
ETHYLENE
EXCITED STATES
HYDROCARBONS
INFORMATION
MATHEMATICAL MODELS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
THEORETICAL DATA
VIBRATIONAL STATES