Fig. 4: DFT calculations for CT interaction and band alignments in TPY-TTF OG and Zn-TPY-TTF CPG.

a, b HOMO-LUMO charge-transfer transitions with corresponding contributions from intramolecular and intermolecular charge transfer (CT) for TPY-TTF OG and Zn-TPY-TTF CPG, respectively. c HOMO-LUMO band alignments of TTF(PhCONH2)4 and [Zn(TPY)2]2+ for thermodynamic feasibility of electron transfer in the aqueous medium.