Lyomesophases of C3-symmetrical bipyridine-based discs in alkanes: an x-ray diffraction study

The importance of the role of alkane solvents in the self-assembly process of p-conjugated molecules is well recognized but hardly understood. Here we present our results on the X-ray diffraction studies that we conducted to gain insight into the supramolecular structure of mixtures of a bipyridine-based molecule (1) with alkanes. Independent of the alkane used (linear or branched), above xw>0.06 (with xw being the weight fraction of 1) the mixtures show lyotropic liquid-crystalline behavior. The nature of the lyomesophase depends only on xw and not on the nature of the alkane (linear or branched). A columnar rectangular phase is present when xw > 0.66. Upon dilution of 1, a columnar hexagonal phase is assigned first (0.5