Ho(III)希夫碱大环配合物的合成、晶体结构及对DNA的切割活性

本文合成一个新的希夫碱大环配体硝酸Ho(III)配合物 Ho(H2L)(NO3)2](NO3) (H2L表示大环配体Fig. 1)，并进行了系统的物理表征. 晶体结构研究表明: 配合物晶体结构属六方晶系，P 3(1)21空间群，晶胞参数a=1.47213(7) nm，c=2.8998(3) nm，α=90°，γ=120°，V=5.4424(7) nm 3，Z=6，R＝0.0331, wR＝0.0928。中心离子Ho3+位于隔室大环配体的一侧并于希夫碱大环上的两个酚基氧原子和三个氮原子配位，两个双齿配位硝酸根分别从希夫碱大环平面的两侧与中心离子配位使中心离子形成扭曲的九配位三冠三棱柱配位构型。并通过凝胶电泳实验初步研究了该配合物对pBR322质粒DNA的切割作用。

Synthesis, Crystal Structure and DNA Cleavage of a New Holmium(III) Nitrate with a Schiff-based Macrocyclic Ligand

The title macrocyclic complex Ho(H2L)(NO3)2](NO3) (H2L denotes the macrocyclic ligand, Fig. 1) has been synthesized and characterized by elemental analysis, infrared spectra, and electrospray mass spectra. Its crystal and molecular structures were determined by X-ray diffraction methods. The crystal crystallizes in the hexagonal system, space group P3(1)21 with a=1.47213(7) nm， c=2.8998(3) nm，α=90°，γ=120°，V=5.4424(7) nm 3，Z=6，R＝0.0331, wR＝0.0928。 The central holmium ion was located in one of the compartments of the macrocyclic ligand and was coordinated with two oxygen and three nitrogen atoms of the macrocycle. Two nitrates were chelated in the opposite positions of the macrocycle, and the third one is ionic. So the central ion presented a distorted tricapped trigonal prismatic coordination geometry. The preliminary studies of cleavage of double stranded DNA was demonstrated by electrophoresis gel.