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The importance of diameter-sorted single-wall carbon nanotubes (SWCNTs) non-covalently bound to a donor-acceptor molecular cleft, 1, in prolonging the lifetime of charge-separated states is successfully demonstrated. For this, using a multi-step synthetic procedure, a wide-band capturing, multi-modular, C60-bisstyrylBODIPY-(zinc porphyrin)2, molecular cleft 1, was newly synthesized and shown to bind diameter sorted SWCNTs. The molecular cleft and its supramolecular assemblies were characterized by a suite of physico-chemical techniques. Free-energy calculations suggested that both the (6,5) and (7,6) SWCNTs bound to 1 act as hole acceptors during the photo-induced sequential electron transfer events. Consequently, selective excitation of 1 in 1:SWCNT hybrids revealed a two-step electron transfer leading to the formation of charge-separated states. Due to the distal separation of the cation and anion radical species within the supramolecules, improved lifetimes of the charge-separated states could be achieved. The present supramolecular strategy of improving charge separation involving SWCNTs and donor-acceptor molecular cleft highlights the potential application of these hybrid materials for various light energy harvesting and optoelectronic applications. 

A zinc phthalocyanine-pyrroloperylenediimide dyad connected through a nitrogen heteroatom (PDI-N-ZnPc) has been newly synthesized and characterized. Solvent polarity-dependent singlet-singlet energy transfer and electron transfer quenching were envisioned from absorption and steady-state fluorescence studies. Electrochemical and spectroelectrochemical studies enabled the assessment of the redox potential of the donor and acceptor entities, as well as the spectral characterization of the one-electron oxidation and reduction products. DFT studies were performed to investigate the geometry and electronic structure, as well as the role of N-connectivity in determining the relative orientation of the entities. Further, time-dependent DFT studies helped establish the different excited states responsible for promoting charge separation. An energy diagram was subsequently established to visualize different photo-physical events. Finally, femtosecond transient absorption spectral studies were performed in both nonpolar and polar solvents to observe energy and electron transfer events. The kinetic data were subsequently analyzed using global and target analyses. The persistence of the charge-separated state in the present dyad, compared with earlier reported ZnPc-PDI dyads featuring carbon-carbon connectivity, was the primary outcome of the present study, highlighting the role of heteroatom linkage in regulating electron transfer dynamics in donor-acceptor conjugates.