Preparation and Characterization of Organosiloxanes with A Liquid Crystalline Trans-4-Pentylcyclohexanoate Moiety

Abstract

In the course of this research, we successfully created three series of liquid crystalline compounds featuring the trans-cyclohexane structure. One series of compounds featured a double bond at the terminal position of the molecules, whereas the remaining two series incorporated disiloxane and trisiloxane groups. Each series comprised five spacers of different lengths, specifically 3, 4, 5, 6, and 11 methylene units. We identified the structures of the synthesized compounds using Nuclear Magnetic Resonance spectroscopy and characterized their liquid crystalline behavior through thermal analysis and polarized optical microscopy. The results revealed that both the length of the spacer and the presence of siloxane groups significantly influenced the liquid crystal phase transitions, transition temperatures, and temperature ranges. These findings provide valuable insights for designing and developing new liquid crystal materials with tailored properties for various applications.