MOLECULAR CONFORMATIONAL-CHANGES IN THE SMECTIC-C, SMECTIC-A AND NEMATIC PHASES OF TBBA

The relative temperature dependence of several DMR splittings in the smectic C, smectic A and nematic phases of TBBA is discussed quantitatively in terms of internal rotations and changes of the most probable molecular conformation. It is shown that in these phases, the conformation is not planar. The mean dihedral angles between some rigid molecular fragments are estimated and compared with theoretical calculations. A discussion in terms of two order parameters is also made in the Appendix.