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Abstract
We prepared novel S‐shaped liquid crystal oligomers, the 4,4′‐bis(ω‐(2‐(ω‐(4‐(cyanophenyl)phenyloxy)alkyloxy)phenyloxy)alkyloxybiphenyls (S‐n ), and investigated their transition behaviour. The oligomer with even‐numbered spacers (S‐6) exhibited a nematic phase, whereas the oligomer with odd‐numbered spacers (S‐7) exhibited nematic and smectic A phases. Transition properties of the S‐shaped oligomers are compared with those of the corresponding monomeric and U‐shaped dimeric compounds. The entropy changes associated with the I–N transition for the oligomers were found to have small values, similar to that of the monomeric compound. A biaxial smectic phase was induced below the SmA phase in some binary mixtures of S‐6 and a phenylpyrimidine derivative (8‐PYP‐6O). On the other hand, the SmA phase was stabilized in the mixtures of S‐7 and 8‐PYP‐6O. We discuss the transition behaivour of the S‐shaped oligomers in terms of their molecular shape.
Acknowledgement
This work was supported by Aomori Prefecture Collaboration of Regional Entities for the Advancement of Technological Excellence, JST and a Grant for Priority Research Designated by the President of Hirosaki University.