MOLECULAR PROPERTIES OF SOME NEMATIC LIQUIDS. I. MAGNETIC SUSCEPTIBILITY ANISOTROPY AND ORDER PARAMETER

Abstract

The diamagnetic susceptibility of a number of 4,4'-disubstituted phenyl benzoates and two isomers of 4,4'-disubstituted phenyl thiobenzoates are reported as a function of temperature in the solid, nematic and isotropic phases. The Merck nematic phases ZLI 1052 and ZLI 389 are also studied. The order parameters are calculated using an estimated value for the molar susceptibility anisotropy. The effect of the terminal substituents and central groups on the magnetic anisotropy is discussed. For compounds with similar chemical framework the order parameters in the case of thioesters and nitriles are higher than in the case of esters and alkoxides