First Examples Exhibiting both Double Melting Behavior and Mesomorphism in a Series of Long Chain Substituted Compounds: 1,3-Di(p-n-alkoxyphenyl)propane-1,3-dione

Abstract

A new series of β-diketones substituted by the same kind of chains, (alkoxy groups) having different lengths (C_nO-Diketone, n = 1-12), has been synthesized. It was found that C_nO-Diketone shows triple melting behavior for n = 1, double melting behavior for n = 2-7, and smectic mesomorphism for n = 8-12. It is the first example exhibiting both double (triple) melting behavior and mesomorphism in a series of long chain substituted compounds, so far as we know. Furthermore, it is noteworthy that the critical change from double melting behavior to mesomorphism occurs between n = 7 and n = 8, which is also the first example in the long chain substituted compounds, so far as we know.