Synthesis, spectroscopic and redox properties of the mononuclear NiII, NiII(BPh2)2 containing (B-C) bond and trinuclear CuII-NiII-CuII type-metal complexes of N,N′-(4-amino-1-benzyl piperidine)-glyoxime
Synthesis, spectroscopic and redox properties of the mononuclear NiII, NiII(BPh2)2 containing (B-C) bond and trinuclear CuII-NiII-CuII type-metal complexes of N,N′-(4-amino-1-benzyl piperidine)-glyoxime
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N,N′-(4-氨基-1-苄基哌啶)-乙二肟单核NiII、NiII(BPh2)2及三核CuII-NiII-CuII型金属配合物的合成、光谱及氧化还原性质
DOI：
10.1007/s12039-009-0005-z
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发表时间：
2009
影响因子：
1.7
通讯作者：
I. Yilmaz
中科院分区：
文献类型：
--
作者：
A. Kilic;E. Taş;I. Yilmaz
以4-氨基-1-苄基哌啶为原料，在- 15℃的绝对四氢呋喃条件下，与抗二氯酰肟反应合成了含有4-氨基-1-苄基哌啶基团N，N′-（4-氨基-1-苄基哌啶）-乙肟的新维二肟配体（LH2）。得到了金属/配体比为1:2的单核零金属配合物。提出了该配体的niii配合物为方形平面几何。红外光谱表明，该配体以四齿方式作用，配位LH2to NiIIion的n4给基。红外光谱对[Ni(LH)2](1)金属配合物中氢键（O- h··O）的检测支持了单核配合物的方形平面mn4配位。[Ni(L)2(BPh2)2](2)配合物中氢键（O- h··O）的消失表明BPh2+的包覆基团（BPh2+阳离子形成bph4阴离子）附着在主肟核上。用核磁共振波谱法测定了[Ni(LH)2](1)和[Ni(L)2(BPh2)2](2)金属配合物的mn4配位。在三核CuII-NiII-CuIImetal配合物中，NiIIion通过亚胺基的配位而居中于主肟核，而两个cuiiion则配位于肟基的二阴离子给氧体，并与1,10-菲罗啉、2,2′-联吡啶和4,4′-联吡啶配体相连。通过元素分析、FT-IR、UV-Vis、1H和13c - nmr、磁化率、摩尔电导率、循环伏安法、质谱和x射线粉末技术对配体及其单核和三核金属配合物进行了表征。循环伏安结果表明，与[Ni(LH)2]相比，[Ni(L)2(BPh2)2]的阴极峰电位向负值偏移，这可能是由于BPh2+桥接络合物的形成减少了金属肟部分的反向给体的影响。此外，三核CuII-NiII-CuIImetal配合物的形成对单核[Ni(LH)2](1)配合物的CV行为产生了相当大的变化。对[Ni(L)2(BPh2)2](2)的光谱电化学研究表明，由于肟核中镍的减少，光谱强度（λ=在364 nm处，分配到ton→π*跃迁）下降，在460 nm左右出现了一个新的低强度宽带。
The novelvic-dioxime ligand containing the 4-amino-1-benzyl piperidine group,N,N′-(4-amino-1-benzyl piperidine)-glyoxime, (LH2) has been prepared from 4-amino-1-benzyl piperidine with anti-dichloroglyoxime at −15°C in absolute THF. Mononuclear NiIImetal complex has been obtained with 1: 2 metal/ligand ratio. The NiIIcomplex of this ligand is proposed to be square planar geometry. IR spectra show that the ligand acts in a tetradentate manner and coordinates N4donor groups of LH2to NiIIion. The detection of H-bonding (O-H···O) in the [Ni(LH)2] (1) metal complex by IR spectra supported the square-planar MN4coordination of mononuclear complex. The disappereance of H-bonding (O-H···O) in the [Ni(L)2(BPh2)2] (2) complex shows that the BPh2+-capped groups (BPh2+cation formed BPh4anion) attaches to the main oxime core. MN4coordination of the [Ni(LH)2] (1) and [Ni(L)2(BPh2)2] (2) metal complexes were also determined by1H-NMR spectroscopy. In the trinuclear CuII-NiII-CuIImetal complexes, the NiIIion centered into the main oxime core by the coordination of the imino groups while the two CuIIions coordinate dianionic oxygen donors of the oxime groups and linked to the ligands of 1,10-phenanthroline, 2,2′-bipyridine, and 4,4′-bipyridine. The ligand and their mono and trinuclear metal complexes were characterized by elemental analyses, FT-IR, UV-Vis,1H and13C-NMR spectra, magnetic susceptibility measurements, molar conductivity, cyclic voltammetry, mass spectra and X-ray powder techniques. The cyclic voltammetric results show that the cathodic peak potential of [Ni(L)2(BPh2)2] shifted toward more negative value compared to that of [Ni(LH)2], probably due to a decreasing effect of back donation of metal-oxime moieties as a result of the BPh2+-bridged complex formation. Also, the formation of the trinuclear CuII-NiII-CuIImetal complexes caused considerable changes on the CV behaviour of mononuclear [Ni(LH)2] (1) complex. The spectroelectrochemical study of [Ni(L)2(BPh2)2] (2) showed distinctive spectral changes that the intensity of the band (λ= at 364 nm, assigned ton→π* transitions) decreased and a new broad band in low intensity about 460 nm appeared as a result of the reduction of the nickel centered in the oxime core.