Preparation and Characterization of Novel Carbosilane Dendrimers Carrying Mesogens

A series of new carbosilane dendrimers carrying cyanobiphenyl derivatives was prepared starting from the tertiary core molecule, triallylphenylsilane. The phase transition of the dendrimers depends on the dendrimer generation, and the spacer lengths were investigated by using differential scanning calorimetry (DSC) and an optical polarizing microscope. All of the dendrimers prepared exhibited smectic A phases. The phase behavior on the phase-transition pattern of the DSC curve and the texture appearances of G2-mesogen(5) carrying twenty-seven mesogens were observed to be similar to that of the reported G2 dendrimer prepared starting from the quarternary core molecule, tetraallylsilane, carrying thirty-six mesogens.