Structural characterization of thermotropic liquid crystalline dihydroxydicarbosilane mesophase

Molecular mechanics (MM) calculations of the structure formed by bis(hydroxydimethylsilyl)methane [(CH3)(2)(HO)Si](2)CH2 (MDCS) molecules have been performed. The calculations lead us to conclude that MDCS can form a columnar liquid crystalline phase which consists of supramolecular H-bonded associates similar to those found earlier for siloxane compounds of the same type. Synthesis of MDCS was performed. IR, NMR, DSC and XRD (powder and single crystal) investigations have shown the existence 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.