http://worldcat.org/entity/work/id/137446337

Polarizabilities of Trans and Cis Polyacetylene and Interactions Among Chains in Crystalline Polyacetylene

In this paper, we use the semi-empirical Hartree-Fock method, introduced within the finite electric field perturbation approach, to calculate the molecular and pi-system polarizabilities of trans and cis polyene H( -CH=CH- ) nH (n = 3,4,5 ...,18). The result is that for a given n, the order of both molecular and pi-system polarizabilities of polyene is trans> cis. This result is consistent with the order of experimental values of trans and cis hexatriene. When the n increases from 3 to 18, the contribution of pi-system polarizability to the molecular polarizability increases from 45% to 70%. Using these results, we have extrapolated the polarizabilities of both trans and cis polyacetylene. The order is trans> cis. These results and crystal parameters lead to an estimate of the dispersion energies among polyacetylene chains. The result is also E sub disp (trans)> E sub disp (cis).

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