A variety of phenylbenzoates of the type [GRAPHICS] with both X and Y being the carbonyL containing chains (CH2)(n)COR (n = 0 - 1), (CH2)nCO2R and (CH2)(n)OCOR (R = alkyl chain) in various combinations were synthesized and their mesomorphic properties studied to determine if an additive effect occurs when these chains are incorporated into the same molecule. No reliable additive effect could be found. Instead, clearing temperatures often seemed to be closer to the clearing temperature of the parent single carbonyl containing chain ester with the higher clearing temperature. An attempt was also made to improve the properties of the esters 1 with X or Y being I, F, CN or NO2 by using a carbonyl containing chain as the second substituent and assuming an additive effect. However, such an effect was also not observed in these esters. Smectic C phases were found in some of the esters with X = CN which is rare for compounds containing this substituent.