The Odd-Even Effect in Steryl ω-Phenylalkanoates

Abstract

We became interested in the ω-phenylalkanoates of cholesterol after it was reported⁽¹⁾ that of the first five members investigated only the odd esters were mesomorphic, but not the even members cholesteryl phenylacetate and 4-phenylbutyrate. However, we found a cholesteric mesophase in cholesteryl 4-phenylbutyrate. We also observed that the temperature values of the cholesteric-isotropic transitions fell on two curves, with the odd-numbered members forming the higher branch, and the even-numbered members forming the lower branch. The two curves did not merge, and no smectic-cholesteric transitions were observed except in cholesteryl 8-phenyloctanoate, the last member studied in that investigation.⁽²⁾