Branching effect on triphenylamine-CF3 cyanostilbenes: enhanced emission and aggregation in water

Six linear and branched α-cyanostilbene derivatives bearing a triphenylamine donor and an electron withdrawing trifluoromethyl group on the phenyl ring and a cyano acceptor on the double bond were synthesized and examined for their absorption and emission properties in solution and the solid state. The molecules exhibit characteristic solvatochromic emission and aggregation induced emission in water. Interesting absorption and emission changes were observed upon branching with the third arm exerting a negligible effect. Dropcast SEM images of these molecules in water reveal unique morphological features with the formation of uniform structures. The triply branched triphenylamine forms a stable organogel aided by intermolecular interactions. The results are substantiated using DFT calculations.