本文合成了一种新的双核稀土配合物Na4Eu2L2·3NaNO3·12H2O [L=(2,6-bis[bis (carboxylatomethyl)amino]methyl-4-nitrophenolate),以下缩写为NO2-HXTA],并用红外光谱(IR)、元素分析(EA)等手段对其结构进行了表征.用凝胶电泳实验研究了该双核稀土配合物与pBR322 DNA的作用,发现在37℃时与DNA的切割作用不明显;但在50℃,pH 7.2时,配合物在较低浓度(50 μmol /L )下即可将70%的超螺旋DNA(CCC带)转化为缺刻产物(OC带);此外,用光谱学手段研究了双核稀土配合物与小牛胸腺(CT) DNA的作用,结果表明,配合物的加入使CT DNA的最大吸收峰(λmax=260 nm)增色和蓝移,并且使溴化乙锭EB-DNA复合物体系的荧光强度减弱.%A new dinuclear metal complex,Na4Eu2L2·3NaNO3·12H2O (here L=2,6-bis[bis(carboxylatomethyl)amino]methyl-4-nitrophenolate and abbreviated as NO2-HXTA) was synthesized and characterized by IR and EA.Through gel electrophoresis experiments,we found that the complex is capable of promoting the cleavage of pBR322 DNA at 50 ℃ and pH7.2,translating 70% of the supercoiled DNA into nicked form at a concentration as low as 50 μmol /L.Investigation on the interaction between the complex and CT DNA indicated that the absorbance of CT DNA was increased and the maximum peak (λmax=260 nm) blue-shifted,while the intensity of fluorescence spectra of EB-DNA was gradually weakened.
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