Abstract
Members of the truxene derivatives series Cn HATX have been investigated by density-temperature—for n = 8 to 12—and thermobarometric—for n = 8, 10 to 13—measurements. Volume changes for transitions, density, partial molar volumes for aromatic cores and CH2 groups, thermal expansion and isothermal compressibility coefficients are determined for the discoid nematic ND and rectangular columnar Drd mesophases. Pressure-temperature phase diagrams for n = 8, 10 to 13 are given; a monotropic phase is observed under atmospheric pressure for n = 10 and 11; it seems it is an hexagonal columnar mesophase Dh. Maximum for the boundary line for Dh and ND or Drd phases for n = 10 and 12 are predicted.