A comprehensive series of (R—(4-substituted-phenoxy)propanoates and (R—(4-substituted-phenoxy)propanonitriles have been prepared. A wide variety of 4-substituents and ester functions have been examined to determine how the position of the chiral centre affects the cholesteric phase formation in these classes of materials; the synthesis of these novel materials, their transition temperatures and a procedure for assessing their optical purity are described and discussed. Mesogenicity is significantly depressed if the chiral centre is placed centrally within the molecule.