Maksimenko S. Synthesis, properties and mesomorphic ability of the alkandioles, 1,3-dihydroxybenzene, 2,7-dihydroxynaphthalene substituted benzoyloxybenzoic acids esters

The work is devoted to studying of influence of the molecular structure features of esters of alkandioles, 1,3-dihydroxybenzene, 2,7-dihydroxynaphtalene and substituted benzoyloxybenzoic acids on fonding of ferroelectric "banana" B2-phase. The new method of synthesis of 4-alkoxybiphenyl-4 -benzoylchlorides, allowed to shorten the number of the stages and increase the yield of purpose compounds is worked out. It is obtained the data of influence of the bromine atom position on mesogenic ability of esters of alkandioles, 1,3-dihydroxybenzene, 2,7-dihydroxynaphtalene and bromine substituted 4-(4-alkoxybenzoyloxy)benzoic acids. Influence of position and number of bromine atoms on a vitrify ability 2,7-dihidroxynaphtalene esters is first stadied. It is determined that 1-brom-2,7-dihydroxynaphtalene diesters fond a vitrified stage from B2-mesophase. Beeng of bromine atom in peripheral aromatic cycles negatively influences on mesogenic ability of compounds and results to a transition from anisotropic stage in vitrified one. Influence of position of the substituents at the central aromatic cycle and also structures of lateral fragments on the mesomorphism of new symmetric esters of 1,3-dihydroxybenzene and formation of B1 "banana" mesophase modification is investigation at esters of 1,3-dihidroxybenzene, that contain for three aromatic cycles in lateral fragments. Formation of the ferroelectric B2 phase by the synthesized asymmetrical esters of 1,3-dihydroxybenzene is cansed by sufficient length of terminal substituent (twelve and more carbon atoms) and change of one structural element in a lateral fragment (additional aromatic cycle or alkyl terminal group).