Mesogenic Ni(II) complexes of C_s symmetry forming Col_h phase by dipole-dipole interaction

Abstract

New Ni(II) metallomesogens are described, having their chelating centre constructed from two non-identical fragments: enaminoketone and barbiturylidenomethyleno-amine rings, thus low C_s symmetry. Various side chains were attached to the mesogenic core. Despite a triangular molecular shape, almost all synthesised compounds exhibit a liquid crystalline hexagonal disordered columnar phase (Col_h) with high clearing temperature. The ability to create the columnar phase is probably connected with the permanent dipole moment appearing in the non-symmetric molecules and dipole–dipole interactions between molecules in columns.

This work is dedicated to Prof. Michael Hanack, with best wishes, on the occasion of his 80th birthday.

Keywords:

• metallomesogens
• liquid crystals
• dipole moment
• Claisen formylation

Acknowledgement

This work was supported by FNP Program TEAM/2010-5/4.

Notes

This work is dedicated to Prof. Michael Hanack, with best wishes, on the occasion of his 80th birthday.