A variety of fairly air-stable complexes were prepared by straightforward reactions of NbX5 (X = F, Cl) with a series of potential bidentate (N,O)- and (O,O)-donor ligands in CH2Cl2. NbF5 reacted with equimolar amounts of 2-[(2,6-diisopropylphenyl)iminomethyl]phenol (dpimpH) and 2-benzoyl-6-hydroxy-6-phenylpentafulvene (bhpfH) to afford the mononuclear complexes NbF5[κ1(O)-OC6H4CHNHC6H3(CHMe2)2], 2, and NbF5[κ1(O)-bhpfH], 7, respectively. The 1 : 1 reactions of NbF5 with salicylaldehyde oxime (saoH2) and 2-phenylaminoethanol gave the hexafluoroniobato salts [NbF4κ1(O)-ON(H)CHC6H4OH}2][NbF6], 3, and [NbF4κ1(O)-OCH2CH2NH2Ph}2][NbF6], 6, respectively. The syntheses of 2, 3 and 6 are accompanied by oxygen to nitrogen intramolecular H migration, leading to the formation of metal–alkoxide moieties. The parallel chemistry of NbCl5 is characterised by HCl release. The 1 : 1 reactions with dpimpH, saoH2 and bhpfH yielded, respectively, the ionic complex [NbCl2κ1(N):κ1(O)-dpimp}2][NbCl6], 4a, the neutral-dinuclear Nb2Cl7[κ1(O)-saoH][κ2(O)-sao], 5, and the mononuclear NbCl4[κ2(O)-bhpf], 8. The tantalum species [TaCl2κ1(N):κ1(O)-dpimp}2][TaCl6], 4b, was prepared from TaCl5/dpimpH. The new products 2–8 were fully characterized by analytical and spectroscopic techniques. Moreover the solid state structures of 2 and 8 were ascertained by X-ray diffraction studies; the structure of 2 exhibits an intramolecular bifurcated N–H⋯(O,F) hydrogen bond. DFT calculations were carried out in order to predict the lowest energy structures in the distinct cases, showing generally good agreement with the experimental data.
通过 NbX5(X = F、Cl)与一系列潜在的双齿(N,O)- 和(O,O)- 供体
配体在
CH2Cl2 中的直接反应,制备出了多种相当稳定的空气配合物。NbF5 与等摩尔量的 2-[(2,6-二异丙基苯基)亚
氨基甲基]
苯酚(dpimpH)和 2-苯甲酰基-6-羟基-6-苯基五烯烃(bhpfH)反应,分别得到单核配合物 NbF5[κ1(O)-OC6H4CHNHC6H3(CHMe2)2], 2 和 NbF5[κ1(O)-bhpfH], 7。1 :NbF5 与
水杨醛肟(saoH2)和 2-苯基
氨基
乙醇发生 1 : 1 反应,分别得到六
氟铌盐[NbF4κ1(O)-ON(H)CHC6H4OH}2][NbF6]3 和[NbF4κ1(O)-OCH2CH2NH2Ph}2][NbF6]6。2、3 和 6 的合成伴随着分子内从氧到氮的 H 迁移,从而形成金属氧化物分子。NbCl5 的平行
化学反应以释放 HCl 为特征。1 :与 dpimpH、saoH2 和 bhpfH 的 1 : 1 反应分别产生了离子复合物 [NbCl2κ1(N):κ1(O)-dpimp}2][NbCl6], 4a,中性-非核 Nb2Cl7[κ1(O)-saoH][κ2(O)-sao], 5 和单核 NbCl4[κ2(O)-bhpf], 8。由 TaCl5/dpimpH 制备出了
钽物种 [TaCl2κ1(N):κ1(O)-dpimp}2][TaCl6],即 4b。分析和光谱技术对新产物 2-8 进行了全面表征。此外,还通过 X 射线衍射研究确定了 2 和 8 的固态结构。为了预测不同情况下的最低能量结构,我们进行了 DFT 计算,结果显示与实验数据基本吻合。