Kinetics of Non-Radiative Rotational Isomer Butane Transitions
G. Keković a, D. Raković a and D.M. Davidović b
a Faculty of Electrical Engineering, P.O. Box 35-54, 11120 Belgrade, Serbia
b Vinca Institute of Nuclear Sciences, Belgrade, Serbia
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A theoretical model for calculation of equilibrium concentrations of isomeric butane molecule forms, and also the forms of hydrocarbons of the alkene series, is proposed. We considered the changes of internal rotational potential energy in respect of reaction coordinate, of rapid conversion of butane isomers from one form to another at room temperature. This is very important for better understanding of the nature of chemical reactions in butane, because the changes of internal rotational potential energy reflect conformational transitions of butane and changes of its chemical and physical properties. The presented model is based on Gribov's system of kinetic equations for isomer-isomer transitions. The canonical ensemble is used to calculate the room temperature probabilities of the rotoisomer conformational states as functions of dihedrial angle, and the obtained results are in good agreement with available ones. Also, in a sense of calculated lifetime of unstable rotoisomers (<10-10 s), our results are comparable with coupled cluster and density functional calculations on alkene derivatives.
DOI: 10.12693/APhysPolA.115.775
PACS numbers: 82.20.Bc, 82.20.Ln, 82.20.Pm