Polysubstituted triphenylenes with active groups. Molecular parameters, synthesis, structure, and mesomorphism

Molecular parameters of hexaalkoxybiphenylenes with different substituents on the periphery of the triphenylene nucleus of known and hypothetical stru ctures are calculated, The probability of a discophase for compounds of thi s series is estimated from molecular parameters. Several compounds of this series having polar groups (NO2, NH2) in the I position of the triphenylene nucleus have been synthesized The compounds synthesized were investigated by thermopolarizing microscopy and X-ray diffraction analysis. The data on the mesomorphism of the new compounds are in good agreement with our predic tion that alkoxytriphenylenes with polar groups have a discophase. It is es tablished that introduction of an electron-accepting group at position I of the triphenylene nucleus expands the temperature range of existence of the discophase to room temperature. On the contrary, introduction of an electr on-donating group narrows this interval. Compounds of this series presumabl y have a hexagonal columnar structure.