SYNTHESIS AND DETECTION OF LIQUID CRYSTALS OF THE PYRIMIDINE FAMILY
Long Ling, Rong Guo Bin(East China University of Soience and Technology Department of Chemistry,Shanghai 200237)
Four series of 2-biphenyl and 2-phenyl as well as 2-laterally monofluoro-substi-ituted phenyl pyrimidines were synthesized and their mesomorphic and some physical properties were investigated. They are relatively lowmelting point with transition phases of I -SA-Sc and wide-range Sc phase. The compounds with extra fluorine especially in 2'-position (2) have lower melting points and phase - transition temperature, dielectric anisotropies become negative. It also can be seen that compound 3 have much greater smectic tendencies (particuiarly Sc) , but smectio phase was almost disappeared in 2. These compounds have been used as excellent hosts materials for TN and FLC systems.