Fluorinated metallomesogens - lamellar versus columnar phase formation

Two series of tetradental cis-enaminoketone Ni(II) and Cu(II) complexes with their mesogenic core substituted by different combination of hydrocarbon or fluorocarbon chains have been synthesized. Depending on the type and position of the substituted groups, compounds reveal either calamitic or columnar mesophases. Replacing the alkyl chains by perfluorinated chains stabilizes the columnar phase. A unique phase sequence of isotropic-columnar hexagonal-re-entrant isotropic-smectic (I-Col(h)-I(re)-SmA) has been observed on cooling for some of the obtained compounds.