Interaction of Indenopyridines with [60]-fullerene: A spectroscopic and computational study

Heterocyclic polynuclear planar indenopyridines (I1, I3 and I4) revealed superior wrapping of [60]-fullerene and formed stable ground state equilibrium defined via formation of absorption isosbestic and isoemissive as well. All three indenopyridines showed almost similar order of ground state formation constant both in Benesi-Hildebrand and in Stern-Volmer methods with [60]-fullerene in toluene medium. Density functional theory (DFT) based computation warranted the experimental finding in terms of loss of planarity of indenopyridines, FMO features to define electron donor and acceptor, electrochemical indices to affirm the direction of electron swing and finally time dependent density functional theory (TD-DFT) calculation showed that HOMO to (LUMO+2) has been found to be the most pronounced transition for the strongest binding with 14.