| In the21st century, human beings have to face two big problems, the energycrisis and environmental pollution. Solar energy is an ideal alternative energy due toits clean, safe and lowcost advantages and available in any geographical conditions.Donor-acceptor arrays attract much attention because of their potential photoinducedintramolecular/intermolecular electron transfer to generate charge-separated states,which are very important for the use of solar energy. Porphyrin-perylene bisimidedyads are promising Donor-acceptor arrays for their good thermal stability, highenergy and electronic transmission efficiency and wide region of photo-response.We synthetized a new porphyrin-perylene dyad (ATPP-BAHPDI) linked by atriazine group and the structure was confirmed by1H NMR and MS. The uv-visiblespectra show that the interaction between ATPP and BAHPDI was very weak in theground-state. Results obtained from the cyclic voltammetry test indicate thatphotoinduced electron transfer from the excited ATPP to BAHPDI is possible whenthe ATPP group was excited. Fluorescence quenching of the dyads exhibit thatelectron transfer from ATPP to BAHPDI and energy transfer from BAHPDI to ATPPoccurred. Transient absorption spectra show that a charge-separated state(ATPP~+-BAHPDI~-) forms upon excitation, followed by a recombination process toform triplet BAHPDI. The lifetime was estimated as6.9ns and146.5μs for thecharges-separated state and the triplet BAHPDI.A new zinc porphyrin-perylene dyad (TPPZn-BPHPDI) linked by a coordinatebond was also synthesized and the structure was confirmed by1H NMR. Theuv-visible spectra showed that the interaction between TPPZn and BPHPDI was veryweak in the ground-state. Fluorescence titration results show that the equilibriumconstant of the coordination reaction was5.32×10~4. Transient fluorescence spectraindicate that energy transfer happens from singlet BPHPDI to TPPZn. Transientabsorption spectra showed that energy transfer happens from triplet TPPZn to tripletBPHPDI. |
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