STRUCTURAL CHARACTERIZATION OF THERMOTROPIC LIQUID-CRYSTALLINE DIHYDROXYDICARBOSILANE MESOPHASE

Molecular mechanics (MM) calculations of the structure formed by bis(h ydroxydimethylsilyl)methane [(CH3)(2)(HO)Si](2)CH2 (MDCS) molecules ha ve been performed. The calculations lead us to conclude that MDCS can form a columnar liquid crystalline phase which consists of supramolecu lar H-bonded associates similar to those found earlier for siloxane co mpounds of the same type. Synthesis of MDCS was performed. IR, NMR, DS C and XRD (powder and single crystal) investigations have shown the ex istence of a LC phase in a narrow temperature range. The computational and experimental results suggest the existence of similar columnar LC phases in a wider temperature range for Et-, Pr-, and Bu-substituted bis( hydroxydialkylsilyl)methane.