DIELECTRIC AND ELASTIC PROPERTIES OF A NEMATIC PHASE INDUCED BY CHARGE-TRANSFER INTERACTION IN A BINARY-SYSTEM CONTAINING DISK-SHAPED MOLECULES

The dielectric constants and the elastic coefficients for splay (K1) and bend (K3) of the charge transfer induced nematic (N(c)) phase of tridecyl pentakis(phenylethynyl)phenyl ether (1) doped with different amounts of 2,4,7-trinitrofluorenone (2) were determined by studying the electric field induced bend deformation using the capacitance method. A negative dielectric anisotropy was observed. For the bend elastic constant K3 values up to 22 x 10(-12) N are found which are one order of magnitude higher than the respective values of discotic nematic(N(D))phases. Values of 0.6-0.8 are obtained for the ratio K1/K3; these show a minimum for the equimolar complex.