Transition Temperatures and Mesophase Identification of Two Homologous Series of Anils

Liquid Crystal Institute, Kent State University, Kent, Ohio, U.S.A. Manuscript received 11 August 1972; revised 5 May 1973; accepted 24 July 1973 Two series, each comprised of fourteen homologs were prepared by condensing 4-n-alkoxy. benzaldehydes with 4-ethylaniline and 4-\(n\)-butylaniline respectively. The homologs were purified and transition temperatures were studied by differential thermal analysis and phase contrast microscopy. The tentative assignments of mesophases by texture observation are presented. Plots of transition temperatures \(vs\) carbon numbers in the chain are given. The mesomorphic to isotropic transition points far even homologs constitute a 'wave shaped' curve while for the odd homologs, a rising curve is found. The smectic-nematic transition curve is a rising one but slightly concave and unlike other series it coincides with the nematic-isotropic curve for odd homelogs