Enhancement of nematic and smectic C phases in soft condensed matter cored by 2, 6-disubstituted naphthalene with varying terminal chains

A series of new symmetric monomer comprising 2,6-dihydroxynaphthalene as central unit with extended side arms made up by biphenyl system and the terminal alkoxy chains, OCnH2n+1 (n = 7–12) have been successfully prepared and their mesomorphic behaviors were investigated. The naphthalene derivative with shorter terminal alkoxy chains ranging from n = 7 to n = 10 were found to display enantiotropic nematic (N) phase. The homologues with undecyloxy and dodecyloxy derivatives are enantiotropic N phase with the emergence of monotropic smectic C phase. The rigidity and polarizability of naphthalene core causes wide N phase transition temperature range.