Synthesis and phase behavior of carbosilane LC dendrimers with terminal mesogenic groups based on anisic acid derivatives

The synthesis of five generations of carbosilane LC dendrimers with termina l mesogenic groups based on anisic acid derivatives which are linked to car bosilane dendritic matrices via an undecylene spacer is described. The stru cture of all new compounds was studied by H-1 NMR spectroscopy and gel perm eation chromatography. The phase behavior of LC dendrimers was studied by D SC and polarizing optical microscopy. It was demonstrated that all the test ed dendrimers display an LC phase in a wide temperature interval. As the ge neration number of dendrimer grows, the isotropization temperature increase s, whereas the enthalpy of isotropization decreases.