Dielectric study of the tilted columnar mesophase in three new chiral metallorganic discotic mesogens

Abstract

Chiral oxovanadium(IV), copper(II) and palladium(II) beta-diketonates show a room temperature tilted columnar mesophase (rectangular P21). The dielectric response of these compounds was measured in the frequency range 10-2-109Hz. Three different relaxation processes have been observed in the columnar phase. One of them is only present in this mesophase and we suggest that it is a Goldstone-like mode, similar to the one present in the helical SmC* phases. In our case the presence of the helix was confirmed by circular dichroism studies.