| Molecular dyads composed of electron donor to a covalently linked acceptor componet have been widely studied as mimics of the natural photosynthetic recation centers and as photochemical molecular devices. Fullerenes have been found to make ideal acceptors in model photosynthetic system, due to their unique three-dimensional structure, the remarkably small reorganization energy, photophysical, electrochemical, and chemical properties. As a kind of special macrocyclic compound, porphyrins are frequently used as donors in artificial photosynthetic systems, owing to porphyrins absorb light much more effectively and wider in UV-Vis region.Fulleropyrrolidine derivative were synthesized by 1,3 dipolar cycloadditon reaction and through EDC-mediated coupling of it to porphyrin synthon. All new compounds were characterized respectively by IR,MS,UV-Vis and elemental analysis.The photochemical property of free base porphyrin-fullerene and zinc porphyrin-fullerene dyads were investigated by steady-state fluorescence spectra. The results showed that the porphyrin emission bands were quenched. And such quenching for the ortho-substitued derivatives is stronger than the para-substituted ones; Red shifts in the fluorescence spectra were observed in modified different electronic effects porphyrin-fullerene dyads.The photovoltaic effect of heterojunction in the photoelectrochemical cell was measured. Influences of various redox couples on the photovoltaic effect were studied. The results showed that: (1) n + n heterojunction electrode formed by porphyrin-fullerene/GaAs was super, especially in the O2/H2O and I2/I3- redox couples. (2) The photovoltaic effect of porphyrin-fullerene/GaAs electrode at 1～2μm for thinckness of porphyrin-fullerene film was the best one. The greatest value of photovoltaic potential was 295 mV in the O2/H2O redox couple. (3) In addition to the photovoltaic effect of porphyrin-fullerene/GaAs electrode was related with linker and metal ions. (4) The photovoltaic effect for the ortho-substitued derivatives is stronger than the para-substituted ones.In conclusion,we synthesized,characterized the porphyrin-fulerene complexes and studied the photochemical property, photovoltaic effect which can provide much convenience for further research of the analogs.
|
PDF Full Text Request