Synthons as building blocks in the synthesis of liquid crystalline multiblock copolymers

Synthetic approaches which allow to insert rather long fragments with exactly definite sequence of several single structural units into polymer chains are considered and summarized. The procedure consists in preliminary formation of such sequences in a form of bifunctional "complex monomer" (synthons) which may undergo a polycondensation with other single or complex monomer to form macromolecule with definite alternation of several single monomers. These synthetic approaches were used for the synthesis of LC multi-block copolymers with definite structure of rigid block.