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Contributions from inner and outer shell electron energies to reaction heats for C 1 , C 2 , and C 3 hydrocarbons
Author(s) -
George P.,
Bock C. W.,
Trachtman M.
Publication year - 1979
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560150408
Subject(s) - atomic physics , shell (structure) , electron , chemistry , electron shell , inner core , physics , ion , materials science , nuclear physics , ionization , organic chemistry , geophysics , composite material
The expectation energy values E K , V ee , V nn , V en , and E T have been calculated for H 2 and the C 1 , C 2 , and C 3 hydrocarbons using a (9,5) basis set and the experimental geometries. Treating the theoretical reaction heat, Δ E T , as the resultant of the nuclear repulsion term, Δ V nn , and the net electron energy term, Δ E elec = Δ E K + Δ V ee + Δ V en , the contribution of inner and outer shell electron energies to Δ E elec , and hence to Δ E T , has been calculated for a large number of hydrocarbon reactions by evaluating the Coulson–Neilson energies η i , where Σ η i = E elec . For the vast majority of reactions, 67/84, the change in inner shell electron energy, (Σ η i ) inner , accounts for more than 10% of Δ E elec , in many cases being as high as 20–35%. Furthermore, in addition to these cases in which the change in inner shell electron energy serves to augment (significantly) the change in outer shell electron energy, there are other cases in which the change in inner shell electron energy either exceeds in magnitude the change in outer shell energy, or is even opposite in sign, indicative of inner and outer shell electrons acting contrariwise. Inner shell electron energies contribute to the reaction heats because they are structure dependent, like the more familiar orbital energies ε, but the dependence is of a different kind.