Pyrrole-Based New Diphosphines: Pd and Ni Complexes Bearing the PNP Pincer Ligand
Pyrrole-Based New Diphosphines: Pd and Ni Complexes Bearing the PNP Pincer Ligand
复制标题
DOI：
10.1021/ic301967r
复制
发表时间：
2012-11-19
影响因子：
4.6
通讯作者：
Chattaraj, Pratim Kumar
中科院分区：
文献类型：
--
作者：
Kumar, Shanish;Mani, Ganesan;Chattaraj, Pratim Kumar
通过Ph2PH与2,5-双(二甲基氨基甲基)吡咯反应合成了一类新型二膦PNP钳配体2,5-双(二苯基膦甲基)吡咯2，收率90%。 Ph2PH与1,9-双(二甲基氨基甲基)二苯基二吡咯基甲烷的类似反应很容易得到PNNP型二膦配体，1,9-双(二苯基膦甲基)二苯基二吡咯基甲烷5，产率92%。这些膦化合物用H2O2和S-8氧化，以非常好的收率得到相应的磷酰基和硫代磷酰基化合物6-9。 PNP 钳配体 2 与 [PdCl2(PhCN)(2)] 在 Et3N 存在下反应，得到单核 Pd(II) 配合物 [PdCl{C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}] 10，产率 87%。相反，在没有 Et3N 的情况下用 [PdCl2(PhCN)(2)] 处理 2 得到双核 Pd(II) 配合物 [Pd2Cl4{mu-C4H3N-2,5-(CH2PPh2)(2)-kappa(PP)-P-2}(2)]，这是根据光谱数据提出的结构。当 2 用 Pd(0) 前体 [Pd-2(dba)(3)] 中心点 CHCl3 处理时，得到双核 Pd(I) 配合物 [Pd-2{mu-C4H2N-2,5-(CH2PPh2)(2)-kappa(PN)-P-2,kappa P-1}(2)], 12，产率 23%。络合物 12 的形成依赖于溶剂，通过变温 H-1 和 P-31 NMR 方法研究，络合物 12 在 CDCl3 中转化为络合物 10。用[Ni(OAc)(2)]中心点4H(2)O处理2得到单核Ni(II)钳配合物[Ni(OAc){C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}]，13，用过量的LiCl或LiBr或KI处理后得到相应的卤离子取代的Ni(II)配合物， [NiX{C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}] (X = Cl、Br 和 I), 14-16，收率非常高。通过单晶X射线衍射法测定了5,2,5-双(二苯基磷酰甲基)吡咯6、10、12和14-16的结构。在12的结构中，观察到对角位置的Pd和P原子之间有两个短接触。为了理解这些弱相互作用，进行了密度泛函理论 (DFT) 计算并给出了相互作用 MO 图。
A new class of diphosphine PNP pincer ligand, 2,5-bis(diphenylphosphinomethyl)pyrrole 2, was synthesized by the reaction between Ph2PH and 2,5-bis(dimethylaminomethyl)pyrrole in 90% yield. The analogous reaction of Ph2PH with 1,9-bis(dimethylaminomethyl)diphenyldipyrrolylmethane readily afforded a PNNP type diphosphine ligand, 1,9-bis(diphenylphosphinomethyl) diphenyldipyrrolylmethane 5 in 92% yield. These phosphine compounds were oxidized with H2O2 and S-8 to give the corresponding phosphoryl and thiophosphoryl compounds 6-9 in very good yields. The reaction of the PNP pincer ligand 2 with [PdCl2(PhCN)(2)] in the presence of Et3N afforded the mononuclear Pd(II) complex, [PdCl{C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}] 10 in 87% yield. Conversely, treatment of 2 with [PdCl2(PhCN)(2)] in the absence of Et3N gave the dinuclear Pd(II) complex [Pd2Cl4{mu-C4H3N-2,5-(CH2PPh2)(2)-kappa(PP)-P-2}(2)], the structure which is proposed based on the spectroscopic data. When 2 was treated with Pd(0) precursor [Pd-2(dba)(3)]center dot CHCl3 the dinuclear Pd(I) complex [Pd-2{mu-C4H2N-2,5-(CH2PPh2)(2)-kappa(PN)-P-2,kappa P-1}(2)], 12, was obtained in 23% yield. The formation of complex 12 is solvent dependent, which transforms into complex 10 in CDCl3 as studied by Variable temperature H-1 and P-31 NMR methods. Treatment of 2 with [Ni(OAc)(2)]center dot 4H(2)O gave the mononuclear Ni(II) pincer complex [Ni(OAc){C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}], 13, which upon treatment with an excess of LiCl or LiBr or KI afforded the respective halide ion substituted Ni(II) complexes, [NiX{C4H2N-2,5-(CH2PPh2)(2)-kappa(PNP)-P-3}] (X = Cl, Br, and I), 14-16, in very good yields. The structures of 5, 2,5-bis(diphenylphosphorylmethyl)pyrrole 6, 10, 12, and 14-16 were determined by the single crystal X-ray diffraction method. In the structure of 12, two short contacts between the diagonally positioned Pd and P atoms are observed. To understand these weak interactions, density functional theory (DFT) calculations were done and an interaction MO diagram is presented.