Evidence of the smectic antiphase in 4-decyloxybiphenyl ester imide derivatives

Abstract

The series of liquid crystalline 4-[(4′-decyloxybiphenyl-4-yl)oxycarbonyl]phthalimide alkane acid methyl esters has been synthesized and studied by DSC, polarized optical microscopy and X-ray diffraction methods. All compounds form a monolayer smectic A phase. It was found that 2-{4-[(4′-decyloxybiphenyl-4-yl)oxycarbonyl]-phthalimido}propanoic acid methyl ester and 4-[(4′-decyloxybiphenyl-4-yl)oxycarbonyl]phthalimidoacetic acid methyl ester also form a ribbon S phase. It was shown clearly that in the former compound, transition from the S _A1 to S phase occurs via an intermediate S _C1 phase. The 6-{4-[(4′-decyloxybiphenyl-4-yl)oxycarbonyl]phthalimido}-hexanoic acid methyl ester exhibits smectic A ₁ and C ₁ phases only.