Transition metal quinone–thiosemicarbazone complexes 1: Evaluation of EPR covalency parameters and redox properties of pseudo-square-planar copper(II)–naphthoquinone thiosemicarbazones
作者:Rajeev C. Chikate、Avadhoot R. Belapure、Subhash B. Padhye、Douglas X. West
DOI:10.1016/j.poly.2005.02.011
日期:2005.6
tridentate ONS donor set for these ligands. A quasi-reversible Cu(II)/Cu(I) redox couple is observed at relatively higher potential (ΔEp = −0.45 to −0.66 V) as a consequence of structural reorganizations, while these complexes exhibit lower redox potentials for the Cu(II)/Cu(III) oxidation process. There exists a linear relationship between the degree of tetrahedral distortion f(α) with spectroscopic
摘要已经对化学计量为[CuLCl]的萘醌-硫代半咔唑的六种铜(II)配合物进行了EPR,光学和氧化还原研究,以阐明其电子结构,金属-配体键合性质和电化学特征。用轴向自旋哈密顿方程模拟的EPR谱图显示出四线图谱,其亚胺/肼基氮原子具有氮超超精细偶合。这些平面络合物具有大量的四面体畸变,从而导致伪正方形平面的几何形状,这从EPR和光学特性得到了证明。对共价参数的评估表明,存在于dx 2-y 2轨道中的未配对电子在配位的硫代半碳氮酮的氮供体位点上花费了大约42-45%的时间,反映了硫中心的π受体性质以及醌分子的电荷积累特性。强烈的π相互作用的存在导致三齿配体形成的整个螯合环发生广泛的离域化。在σ键中观察到中等价,而在平面π键中则具有明显的共价特性。红外光谱数据表明这些配体的三齿ONS供体组。由于结构重组,在相对较高的电位(ΔEp= -0.45至-0.66 V)下观察到准可逆的Cu(II)/ Cu