Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (08): 1968-1974.doi: 10.3866/PKU.WHXB20110821

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Photodimerization Behavior of 7-Hydroxy-4-methyl-8-(4'-methylpiperazin-1'-yl) Methylcoumarin

JIANG Jin-Qiang, GONG Yun-Hua, CHENG Hao, LIU Xiao-Ya, ZHANG Sheng-Wen, XU Jing   

  1. School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P. R. China
  • Received:2011-05-04 Revised:2011-06-03 Published:2011-07-19
  • Contact: JIANG Jin-Qiang, LIU Xiao-Ya
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20704017, 50973044), Qing Lan Project of Jiangsu Province, China, and Scientific and Fundamental Research Funds for the Central Universities, China (JUSRP31003).


The water-soluble coumarin derivative 7-hydroxy-4-methyl-8-(4'-methylpiperazin-1'-yl) methylcoumarin (HMPC) was synthesized by the Mannich reaction between 7-hydroxy-4-methylcoumarin and N-methylpiperazine, which possesses an electrondonating piperazine group with pH responsivity. Since the piperazine group is a pH-sensitive electron donor, the resultant HMPC has interesting photophysical and photochemical properties in different pH solutions. We investigated the characteristic UV absorption and photodimerization behavior of the coumarin derivative. The characteristic UV absorption and also the photodimerization of HMPC, which was irradiated by UV light (λ>310 nm), was effectively changed in different pH solutions. The photodimerization experiments showed that in the neutral solution the dimerization reaction rate was most rapid followed by that in the alkaline solution and it was the slowest in the acidic solution at the same concentration.

Key words: Coumarin, Piperazine, pH-sensitivity, Tertiary amine group, Electron donor, Photodimerization


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