Twin molecules molecular glass structure

Since the twins provide excellent models for investigation of LCP behavior, let us first consider 9AZA9 and 9DDA9. If we use an empirical group additivity approach to the calculation of the heat capacity increase at Tg, by dividing the molecule into mobile structural moieties ("beads") with a contribution of 11.3 J/Kmol for a small "bead" (-CH2-, -CO2-, etc) and approximately twice that amount for "large" beads (-Ph-for example), (19-201 the "expected" values are observed for a number of conventional low molecular mass nematic glasses such as 4-butyl-4 -methoxyazoxybenzene, a close... 

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