Density Functional Study of Crystalline Analogs of Polycarbonates

摘要: Density functional studies have been performed for two crystalline analogs of Bisphenol A polycarbonate (BPA-PC) and the isolated structural unit. The calculations are free adjustable parameters yield equilibrium structures that agree well with available data. Vibrational frequencies calculated molecular For all we energy barriers rotation segments molecule, compared results experiment. All phenylene groups rotate freely in unit, but corresponding π-flips phases hindered by neighboring molecules reflect chain packing. minimum barrier crystal (7.7 kcal/mol) is associated inner ring activation methyl 3.4 kcal/mol, independent packing, carbonyl group 8.7 1...