Molecular Packing Coefficients of the Homologous Series 4,4′-Di-n-alkyloxyazoxybenzene

Abstract

The molecular packing coefficients have been evaluated using the approach of Kitaigorodsky for some members of the series 4,4′-di-n-alkyloxyazoxybenzene. The packing coefficient increases as alkyl chain increases contrary to what is observed for cholesteryl alkanoates. This shows that packing coefficient is intimately related with thermodynamic parameter. These features can be qualitatively explained by considering a mechanical rigid rod model. In principle, this can be used to explain the observed changes in the gradient of S factors in symmetric (4,4′-di-n-alkyloxyazoxybenzene) and asymmetric (p-(p-ethoxyphenylazo) phenyl alkanoates) molecules. The S factor of asymmetric molecules drops off more rapidly than that of symmetric molecules which is in conformity with the packing coefficient calculations.KeywordsLiquid CrystalAlkyl ChainHomologous SeriesCrystal Structure AnalysisSmectic PhaseThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.