Intermolecular interaction between squarylium cyanine and porphyrin

• 作 者: 赵为 侯原军 王雪松 张宝文 曹怡
• 机 构: Institute of Photographic Chemistry, Chinese Academy of Sciences, Beijing 100101, China,Institute of
• 出 处: Chinese Journal of Chemistry
• 发表日期: 1998年01期
• 关键词: porphyrin cyanine chloroform singlet dilute intermolecular quenching definitely

In this paper, the interaction between squarylium cyanine and porphyrin in chloroform is investigated by absorption and fluorescence spectroscopy. Emphasis has been put on the mechanism of intermolecular energy transfer. The overlap integral J between the absorption spectrum of squarylium cyanine and the fluorescence spectrum of porphyrin was calculated, which reveals that the singlet-singlet energy transfer may occur from porphyrin to squarylium cyanine in solution. In comparison of the observed rate constant [kqII=6.1 ×1013 (mol/L)-1·s-1] for fluorescence quenching of porphyrin by squarylium cyanine with the diffusion rate constant in chloroform [kdif=1.1×1010 (mol/L)-1·s-1] and the rate of energy transfer [ket≤6.7×104 (mol/L)-1·s-1 in the experimentally dilute solutions] estimated from Forster formula, the possibility of energy transfer by electron exchange or/and coulombic mechanism could be excluded. So it has been definitely convinced that the intermolecuiar energy transfer between them is

In this paper, the interaction between squarylium cyanine and porphyrin in chloroform is investigated by absorption and fluorescence spectroscopy. Emphasis has been put on the mechanism of intermolecular energy transfer. The overlap integral J between the absorption spectrum of squarylium cyanine and the fluorescence spectrum of porphyrin was calculated, which reveals that the singlet-singlet energy transfer may occur from porphyrin to squarylium cyanine in solution. In comparison of the observed rate constant [kqII = 6.1 × 10 13 (mol / L) -1 · s -1] for fluorescence quenching of porphyrin by squarylium cyanine with the diffusion rate constant in chloroform [kdif = 1.1 × 1010 (mol / L) -1 · s -1] and the rate of energy transfer [ket≤6.7 × 10 4 (mol / L) -1 · s-1 in the experimentally dilute solutions] estimated from Forster formula, the possibility of energy transfer by electron exchange or / and coulombic mechanism could be excluded. So it has been definitely convinced that the intermolecuiar energy transf er between them is