A STUDY OF INTRAMOLECULAR ELECTRON-TRANSF ER PROCESS OF PORPHYRIN-ANTHRAQUINONE UNDER PHOTOINDUCTION .2. PARAMAGNETIC-RESONANCE METHOD

In this paper, the method of paramagnetic resonance was used to study the process of formation of ionic free radicals of a new type of porph yrin-anthrasuinone compounds through intramolecular electron transfer under photoinduction at a low temperature and the effects of different porphyrin ligands, metal-porphyrin, organic bases-axial coordination and solvents on the electron transfer were studied, The experimental r esults indicate that ESR signal intensities of porphyrin and metal-por phyrin were increased with time and tend to be stable after 50 min, Th e signal intensities of PAQ are in the order: H(2)TDMAPPQ>H-2(o-NH)PTr iPPQ>H-2(p-NH)PPQ, while signal intensity of ZnPAQ is greater than tha t of the corresponding PAQ, The formation rate and quantum yield of io nic free group pair P+.-AQ(-.) for PAQ and ZnPAQ in the strong polar s olvent(DMF) are lower than those in weak polar solvent(CH2Cl2). The ax ial coordination with piperidine and imidazole increased ESR signal in tensity of ZnTDMAPPQ, which played a promoting role for the charge sep aration of ZnPAQ, Furthermore, beta-carotene may further enhance the c harge separation of ZnTDMAPPQ with positively charged side chain, Ther efore, this kind of PAQ compounds are ideal ones for photosynthesis.