Relationship between liquid crystal formation and conformations of twin components in liquid crystalline binary systems

Liquid crystalline binary systems (P-n-x: n = number of central methylene units of TN-n, x = mole fraction of TN-n) were built. They consisted of a side-chain polymer with ethyl terminal groups and a twin compound (TN-n) with nitro terminal groups. Liquid crystalline binary systems (T-n-x) of TN-n and a twin compound with butyl terminal groups were also built. The liquid crystallinity of P-n-x and T-n-x was examined. The relationship between the liquid crystallinity and the conformation of TN-n was discussed. The use of both the donor-acceptor interactions and the effects of the conformations led to the formation of novel assemblies. Also, the effects of the conformations were available for the control of smectic orientational structures. All the liquid crystalline binary systems produced induced smectic phases by donor-acceptor interactions between distinct mesogenic groups of the components. Even-membered P-8-x and T-8-x, in which TN-8 component has a linear-like molecular shape, showed the induced smectic A phase. Odd-membered P-7-x and T-7-x, having TN-7 component with a banana-like molecular shape, exhibited the induced smectic CA phase. The orientational structures of the induced smectic phases thus strongly depend on the conformations of the twin components.