Synthesis and Electrochemical Studies of Nickel β-Diketonate Complexes Incorporating Asymmetric Diimine Ligands
作者:Phimphaka Harding、David J. Harding、Nitisastr Soponrat、Kittiya Tinpun、Sirirat Samuadnuan、Harry Adams
DOI:10.1071/ch09232
日期:——
behaviour of the complexes reveals quasi-reversible or irreversible one-electron oxidation to Ni(iii) in the case of the [Ni(tmhd)2(ppaX)] and [Ni(dbm)2(ppaX)] complexes, respectively. The peak potential for oxidation is dependent on the type of β-diketonate ligand but essentially independent of the substituent, X, on the ppaX ligand. The [Ni(β-diketonate)2(ppaX)] complexes (X = F, Cl, Br, and I) also undergo
ppa X (4-X-苯基)-吡啶-2-基亚甲基胺; X = H,Me,Et,OMe,F,Cl,Br和I}与[Ni(β-二酮酸酯)2(H 2 O)2 ] β-二酮酸酯= 1,3-二苯基丙二酸酯(dbm),2 1,2,6,6-四甲基-3,5-庚二酸酯(tmhd)或六氟乙酰丙酮酸酯(hfac)}产生一系列镍配合物。X射线晶体学分析显示八面体配位的镍中心具有顺式排列的β-二酮酸酯配体。该β二酮配位体采用“平面”或“弯曲”的配位模式,而的PPA的芳基环X配体相对于吡啶亚胺单元是扭曲的。配合物的电化学行为表明,在[Ni(tmhd)2(ppa X)]和[Ni(dbm)2(ppa X)]配合物的情况下,准电子可逆或不可逆氧化为Ni(iii)。, 分别。氧化的峰值电势取决于β-二酮酸酯配体的类型,但基本上与ppa X配体上的取代基X无关。[Ni(β-二酮酮酸酯)2(ppa X)]络合物(X = F