Mesomorphic phase transitions and electro-optical properties of benzyl fluoroalkyl ether derivatives

Three series of liquid crystalline (LC) compounds containing benzyl fluoroa lkyl ether groups (BFE), 4-n-propylbicyclohexylbenzyl fluoroalkyl ethers (3 -C2BFE-X, X: fluoroalkyl group), 4-n-alkylcyclohexylbenzyl fluoroalkyl ethe rs (m-C1BFE-X, m: carbon no. of n-alkyl group) and 4-n-alkoxyphenylbenzyl f luoroalkyl ethers (mO-BBFE-X), were newly synthesized for several fluoroalk yl groups (X) such as n-fluoroalkyl, branched fluoroalkyl, and 2-perfluorop ropoxy-2,3,3,3-tetrafluoropropyl. The mesomorphic phase transitions and ele ctro-optical properties were investigated for BFE. 3-C2BFE-X and mO-BBFE-X have SmB phases, and SmA and/or E phases, respectively, while m-C1BFE-X sho wed no mesophases. The occurrence and thermal stability of the LC phases ar e related to the chemical structures of the rigid core part and the termina l groups. The electro-optical properties were investigated for 15 wt % of B FE in host ZLI-1132. It was found that the BFE compounds have a good solubi lity of more than 15 wt % in ZLI-1132 and can be used as a component for lo wering the refractive anisotropy of the host ZLI-1132 solvent.