A coumarin–thiourea conjugate as a fluorescent probe for Hg(ii) in aqueous media with a broad pH range 2–12
作者:Yasuhiro Shiraishi、Shigehiro Sumiya、Takayuki Hirai
DOI:10.1039/b924015b
日期:——
A coumarinâthiourea conjugate (1) behaves as a highly selective fluorescent probe for Hg2+ in aqueous media. The probe 1 shows selective and quantitative fluorescence decrease upon Hg2+ addition in aqueous media with a broad pH range, 2â12. Ab initio molecular orbital calculations reveal that the fluorescence decrease of 1 upon Hg2+ addition is promoted by a Hg2+-induced desulfurization of the thiourea moiety, leading to a decrease in an intramolecular charge transfer (ICT) character of the excited-state coumarin moiety.
香豆素-硫脲缀合物 (1) 可作为水介质中 Hg2+ 的高选择性荧光探针。在较宽的 pH 范围(2-12)的水介质中添加 Hg2+ 后,探针 1 显示出选择性和定量的荧光减弱。从头算分子轨道计算表明,Hg2+ 诱导的硫脲部分脱硫促进了 Hg2+ 添加后荧光强度降低 1,从而导致激发态香豆素部分的分子内电荷转移 (ICT) 特性降低。