Synthesis, phase behaviour and structure of liquid crystalline carbosilanedendrimers with methoxyphenyl benzoate terminal mesogenic groups

For the first time a series of liquid crystalline dendrimers of generations 1 - 4 containing 8, 16, 32 and 64 terminal methoxyphenyl benzoate mesogeni c groups respectively have been synthesised. Mesogenic groups were attached to the carbosilane dendritic matrices with terminal allyl groups through - OOC-(CH2)(10)-Si(CH3)(2)OSi(CH3)(2)- spacer by a hydrosilylation reaction. Structure and purity of all new compounds were confirmed by H-1-NMR spectro scopy and GPC analysis. Phase behaviour of LC dendrimers was investigated b y means of polarising optical microscopy, DSC and X-ray methods. All LC den drimers synthesised display mesophases of smectic types as well as crystall ine phases over wide temperature region. Possible structure and arrangement of molecules of LC dendrimers in these mesophases are discussed.