5-氟水杨酸与铜（II）的络合作用：通过光谱的二维模拟进行的pH电位滴定、紫外可见光谱和电子自旋共振研究

Complexation of 5-fluorosalicylic acid with copper(II): a pH-potentiometric, UV-vis spectroscopic, and electron spin resonance study by the two-dimensional simulation of spectra.

作者信息

Szabó-Plánka Terézia, Gyurcsik Béla, Nagy Nóra Veronika, Rockenbauer Antal, Sípos Rastislav, Sima Jozef, Melník Milan

机构信息

Department of Physical Chemistry, University of Szeged, P.O. Box 105, H-6701 Szeged, Hungary.

出版信息

J Inorg Biochem. 2008 Jan;102(1):101-9. doi: 10.1016/j.jinorgbio.2007.07.019. Epub 2007 Jul 24.

DOI:10.1016/j.jinorgbio.2007.07.019

PMID:17720250

Abstract

The copper(II)-5-fluorosalicylic acid system was investigated in water and 50 v/v% water-methanol mixture by pH potentiometry combined with UV-vis spectrophotometry, and by the two-dimensional ESR simulation method, respectively. The data revealed that the stable paramagnetic mono- and bis(salicylato) copper(II) complexes [CuLH(-1)] and CuL2H(-2) are formed, and at low excess of ligand, the ESR-silent mixed hydroxo complex Cu2L2H(-3) is also a major species. By the two-dimensional ESR simulation method, the species [CuL]+ in the acidic region, and the minor dimer [Cu2L2H(-2)] were also identified, and the cis and trans isomers of CuL2H(-2) were characterized. In frozen solutions, the ESR analysis revealed a slight rhombic distortion of coordination polyhedra for the latter three species.

摘要

通过pH电位滴定法结合紫外可见分光光度法以及二维电子自旋共振（ESR）模拟方法，分别对铜（II）-5-氟水杨酸体系在水和50 v/v%水-甲醇混合溶剂中的情况进行了研究。数据表明，形成了稳定的顺磁性单核和双核（水杨酸根）铜（II）配合物[CuLH(-1)]和CuL2H(-2)，并且在配体少量过量时，电子自旋共振沉默的混合羟基配合物Cu2L2H(-3)也是主要物种。通过二维电子自旋共振模拟方法，还鉴定出了酸性区域中的物种[CuL]+以及次要的二聚体[Cu2L2H(-2)]，并对CuL2H(-2)的顺式和反式异构体进行了表征。在冷冻溶液中，电子自旋共振分析表明后三种物种的配位多面体存在轻微的菱形畸变。