Evidence of the smectic antiphase (C)over-tilde in 4-decyloxybiphenyl ester imide derivatives

The series of liquid crystalline 4-[(4'-decyloxybiphenyl-4-yl)oxycarbonyl]p hthalimide alkane acid methyl esters has been synthesized and studied by DS C, polarized optical microscopy and X-ray diffraction methods. All compound s form a monolayer smectic A phase. It was found that 2-{4-[(4'-decyloxybip henyl-4-yl)oxycarbonyl]phthalimido} propanoic acid methyl ester and 4-[( 4' -decyloxybiphenyl-4-yl)oxycarbonyl]phthalimidoacetic acid methyl ester also form a ribbon S-(C over tilde) phase. It was shown clearly that in the for mer compound, transition from the S-A1 to S-(C over tilde) phase occurs via an intermediate S-C1 phase. The 6-{4-[(4'-decyloxybiphenyl-4-yl)oxycarbony l]phthalimido}hexanoic acid methyl ester exhibits smectic A(1) and C-1 phas es only.