cells having improved viewing angles application_number US 76795777 A description liquid crystal esters in general have comparatively low index of refraction anisotropies but unfortunately they also have high useful temperature ranges above room temperature and slow response times thus they must be admixed with other liquid crystals to form compositions satisfactory for commercial applications mixtures of biphenyl liquid crystals terphenyl liquid crystals and liquid crystal esters have proven to be satisfactory for use in liquid crystal cells that have low voltage requirements fast response times good contrast and wide viewing angles exemplary of the esters useful herein are those having the formula str1 wherein r is an alkyl group of 4 to 10 carbon atoms and str2 wherein r 1 at each occurrence is an alkyl group of 1 10 carbon atoms and x at each occurrence is hydrogen or group with the proviso that at least one x is methyl the biphenyl compounds useful herein have the formula str3 wherein r 2 is alkyl or alkoxy of 3 to 8 carbon atoms the terphenyl compounds useful herein have the formula str4 wherein r 3 is an alkyl or alkoxy group of 4 to 6 carbon atoms useful mixtures of these compounds have an index of refraction anisotropy on the order of from about 0 17 to 0 23 the above mixtures have a viewing angle in a liquid crystal cell that is about 20 u00b0 wider than that of liquid crystal materials having a high index of refraction.