Poly(propyleneimine) dendrimers peripherally modified with mesogens

Poly(propyLeneimine)-based Liquid crystalline dendrimers (PPILCDs) with a relatively flexible dendritic scaffold were successfully prepared by the Michael addition reaction of poly(propyleneimine)s with omega-(4'-cyanobiphenyloxy)alkyl acrylate (1). The structures of PPILCDs were characterized by IR spectroscopy, H-1 NMR spectroscopy, and MALDI-TOF mass spectroscopy. PPILCDs exhibit smectic liquid crystalline natures between -7 and +89 degrees C. The temperature range of the smectic phases expanded with increases in the generation of the dendritic core and the length of flexible spacers. The homeotropic orientation was allowed to take place in PPILCD with the second-generation scaffold, when it was slowly cooled.