SYNTHESIS AND MESOMORPHIC PROPERTIES OF SOME AROMATIC ESTERS CONTAINING 2-BUTYL, 2-OCTYL AND 2-METHYLBUTYL MOIETIES IN THE TERMINAL CHAINS

A variety of esters/thioesters (Z=O/S) with terminal chains containing sterically hindered branched chains containing CH(Me)Et, [GRAPHICS] C H(Me)C6H13 and CH2CH2CH(Me)Et in either the X or Y chain attached to t he benzene ring through an ether oxygen atom, (CH2)nCO2- or (CH2)nOCO- with n = 0-2 and the other chain being R, RO, RCO, RCO2, or ROCO were synthesized as possible new ferroelectric liquid crystals or dopants in mixtures of branched chain phenylbenzoates and phenylthiobenzoates. The main goal was to incorporate substituents that favor larger spont aneous polarization than observed for the thioesters with Z = S and Y = CH2CH2CH(Me)Et and determine if these compounds would have the desir ed N, S(A) and Sc properties. The best properties were observed in the esters with Y = OCOCH(Me)Et. Some cyclohexane diesters and lateral su bstituted esters containing these branched chains were also prepared. Two branched chain esters/thioesters with X = CN were synthesized as p otential cholesteric blue phase materials. These compounds were prepar ed using slightly modified procedures reported earlier. Comparisons in mesomorphic properties are discussed.