Packing polymorphism, odd-even alternation and thermotropic phase transitions in -,-diacylethanolamines with varying -acyl chains. A combined experimental and computational study.

-,-Diacylethanolamines (DAEs) are derived by simple esterification of bioactive -acylethanolamines, which are present in plant and animal tissues. In this study, two homologous series of DAEs, namely -acyl ( = 8-15), -palmitoylethanolamines (N-O16s) and -acyl ( = 8-14), -pentadecanoylethanolamines (N-O15s) were synthesized and characterized with respect to thermotropic phase transitions, crystal structures and intermolecular interactions. In addition, computational studies were performed to get a molecular level insight into the role of different factors in selective polymorphism in N-O16s and N-O15s.