Enforced liquid crystalline properties of dibenzo[a,c]phenazine dimer and self assembly

Abstract

Dibenzo[a,c]phenazine dimers with the following features: (i) short spacer, (ii) peripheral chains shorter and longer than the spacers, and (iii) reduced symmetrical structure of the disc were synthesized. The dibenzo[a,c]phenazine disc has enforced the self-assembly of discotic dimers connected through six methylene spacers to form mesophases through a folded conformation in the mesophase. An X-ray diffraction study pinpoints the preferential intra-molecular bridging conformation of these dimers at the mesophase. These new discotic dimers showed polymesomorphism and glass formation. Interestingly, these discotic dimers form organogels with non-polar hydrocarbon solvents and long chain aliphatic alcohols. A superstructure arising from association of the nanofibers was observed with transmission electron microscopy. © 2011 The Royal Society of Chemistry.