Eight-vertex metallomesogens: Zirconium tetrakis-beta-diketonate liquid crystals

Square antiprism zirconium tetrakis-beta-diketonate complexes with 24 alkox y chains organize in columnar liquid crystal phases. X-ray diffraction and polarized microscopy studies on complexes with n-alkoxy side chains reveale d a columnar hexagonal phase. These sandwich-shaped compounds have much low er transition temperatures than their discotic analogues, which leads to th e desirable attribute of room temperature liquid crystallinity. The additio n of two branching methyl groups to the alkoxy: chains was found to dramati cally alter the properties of these materials. The branched side chain anal ogues exhibited a higher clearing point while the liquid crystallinity is m aintained at room temperature. The branching methyl groups also induced a b ulk reorganization of the material to a rare columnar oblique phase (Col(ob )).