吩噻嗪-Corrole镓(III)配合物的合成、荧光及其光断裂DNA性质(英文)

Synthesis,Fluorescence and DNA Photocleavage Activity of Phenothiazine-Corrole Gallium(III) Complexes

合成了吩噻嗪(PTZ)-corrole二元体1-3及其镓(III)配合物4-6.采用稳态吸收与稳态发射及时间分辨的瞬态光谱技术研究了这几种化合物的光物理特性.结合荧光量子产率和荧光寿命计算得到它们的辐射和无辐射速率常数.稳态吸收光谱表明:几种二元体中,corrole镓(III)单元表现出更强的Soret带和Q带.化合物1-3的荧光量子产率分别是0.156、0.134和0.139,辐射速率常数分别为4.02′107、3.47′107和2.89′107s-1.化合物4-6的荧光量子产率分别是0.502、0.443和0.494,辐射速率常数分别为20.90′107、16.78′107和21.11′107s-1.可见,化合物4-6的荧光量子产率和辐射速率常数均高于化合物1-3.然而,化合物4-6的荧光寿命分别是2.40、2.64和2.34ns,低于自由corrole1-3.琼脂糖凝胶电泳实验表明:在光照的条件下,这些吩噻嗪-corrole镓(III)二元体化合物能够把超螺旋DNA(formI)切割成缺刻型DNA(formII).

Phenothiazine （PTZ）-corrole dyads 1-3 and their gallium（Ⅲ） complexes 4-6 have been synthesized and characterized. The steady-state absorption and emission spectra and the time-resolved fluorescence decay profiles have been measured in toluene. The radiative and nonradiative rate constants have been obtained from the fluorescence quantum yields and monoexponential fluorescence lifetimes. The absorption spectra revealed that the gallium（Ⅲ） corrole dyads exhibit stronger Soret bands and Q bands than free base corrole dyads. The fluorescence quantum yields of 1-3 are 0.156, 0.134, and 0.139, and the radiative rate constants are 4.02×10^7, 3.47×10^7, and 2.89×10^7s-1, respectively. The fluorescence quantum yields of 4-6 are 0.502, 0.443, and 0.494, and the radiative rate constants are 20.9×10^7, 16.78×10^7, and 21.11×10^7 s-2, which are obviously higher than those of the corresponding free base corroles. The lifetimes of 4-6 are 2.40, 2.64, and 2.34 ns, respectively, which are somewhat shorter than those of the corresponding free base corroles. Agarose gel electrophoresis shows that these gallium（Ⅲ） corrole dyads could cleave supercoiled DNA （form Ⅰ） to give nicked-circular DNA （form Ⅱ） under irradiation.