Al-Awadi Nouria, Shuaib Nadia M, El-Dissouky Ali
Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait.
Spectrochim Acta A Mol Biomol Spectrosc. 2006 Sep;65(1):36-43. doi: 10.1016/j.saa.2005.09.024. Epub 2006 Feb 2.
The reaction of NiCl(2).H(2)O with 1-benzotriazol-1-yl-[(p-X-phenyl)hydrazone]propan-2-one, X=H (HL(1)), X=Cl (HL(2)), X=Br (HL(3)) and X=Me (HL(4)), gave the complexes [(HL)NiCl(2)] x nH(2)O and LNi(OH), where L is the monobasic anion of HL(2) or HL(3). The nature of the products is solvent and ligand dependent. The complexes are characterized by elemental analyses, molar conductivity, magnetic moments and spectroscopic (IR and UV/vis) measurements. The IR showed that the ligands act as neutral bidentate coordinated to the nickel(II) through the azomethine nitrogen and carbonyl oxygen atoms in case of [(HL)NiCl(2)] x nH(2)O. In case of LNi(OH), the ligands are monobasic bidentate bonded to the nickel(II) through the azomethine nitrogen and the enolato oxygen atoms. The room temperature magnetic moment values of 1.58-2.49 B.M. for [(HL)NiCl(2)] x nH(2)O and LNi(OH) and their electronic spectral data indicate that these complexes have square planar-tetrahedral equilibrium. The values of 1.61 and 1.58 B.M. for the hydroxo-complexes support their dimeric nature. The electronic spectral of [(HL)NiCl(2)] x nH(2)O and LNi(OH) in pyridine or alpha-picoline indicated the formation of six-coordinate adducts. The hydroxo-complexes reacted with different Lewis bases to give the complexes [L(2)Ni(L(s))(2)], where L(s)=Py, 2-Pic, 3-Pic, 4-Pic or n-PrNH(2). The relationship between the pK(b) of the Lewis base and the upsilon(Ni-O) of the ligand and upsilon(Ni-N) of the Lewis base was studied. The different ligand field parameters are calculated for the parent ligands in solutions and the solid mixed ligand complexes. The data showed that both are associated with a distorted octahedral ligand field around the nickel(II) and the ligand fields in solution are different from that in solid. The extent of distortion for the parent complexes is more than that in the solid adducts. Furthermore, the data showed that the nickel-ligand bonding in LNi(OH) is more covalent than in [L(2)Ni(L(s))(2)].
氯化镍（II）·水合物（NiCl₂·H₂O）与1 - 苯并三唑 - 1 - 基 - [（对 - X - 苯基）腙] - 丙酮 - 2（X = H （HL₁）、X = Cl （HL₂）、X = Br （HL₃）和X = Me （HL₄））反应，生成配合物[(HL)NiCl₂]·nH₂O和[LNi(OH)]₂，其中L是HL₂或HL₃的一元阴离子。产物的性质取决于溶剂和配体。通过元素分析、摩尔电导率、磁矩和光谱（红外和紫外/可见）测量对这些配合物进行了表征。红外光谱表明，在[(HL)NiCl₂]·nH₂O中，配体作为中性双齿配体，通过甲亚胺氮原子和羰基氧原子与镍（II）配位。在[LNi(OH)]₂中，配体是通过甲亚胺氮原子和烯醇式氧原子与镍（II）形成的一元双齿键合。[(HL)NiCl₂]·nH₂O和[LNi(OH)]₂在室温下的磁矩值为1.58 - 2.49 B.M.，其电子光谱数据表明这些配合物具有平面正方形 - 四面体平衡。羟基配合物的磁矩值1.61和1.58 B.M.支持它们的二聚体性质。[(HL)NiCl₂]·nH₂O和[LNi(OH)]₂在吡啶或α - 甲基吡啶中的电子光谱表明形成了六配位加合物。羟基配合物与不同的路易斯碱反应生成配合物[L₂Ni(Ls)₂]，其中Ls = 吡啶、2 - 甲基吡啶、3 - 甲基吡啶、4 - 甲基吡啶或正丙胺。研究了路易斯碱的pK(b)与配体的υ(Ni - O)以及路易斯碱的υ(Ni - N)之间的关系。计算了溶液中母体配体和固体混合配体配合物的不同配体场参数。数据表明，两者都与镍（II）周围扭曲的八面体配体场相关，并且溶液中的配体场与固体中的不同。母体配合物的扭曲程度大于固体加合物。此外，数据表明[LNi(OH)]₂中镍 - 配体键比[L₂Ni(Ls)₂]中的更具共价性。
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