Polarizabilities of trans and cis polyacetylene and interactions among chains in crystalline polyacetylene
Abstract
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-)n-H (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 greater than 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 percent. Using these results, we have extrapolated the polarizabilities of both trans and cis polyacetylene. The order is trans greater than 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) greater than E(sub disp)(cis).
- Publication:
-
Unknown
- Pub Date:
- August 1991
- Bibcode:
- 1991ptcp.rept.....H
- Keywords:
-
- Atomic Interactions;
- Hartree Approximation;
- Molecular Chains;
- Polarization Characteristics;
- Polyacetylene;
- Crystallinity;
- Electric Fields;
- Energy Dissipation;
- Molecular Structure;
- Perturbation Theory;
- Quantum Theory;
- Solid-State Physics