Synthesis and Structural Characterization of Pincer Pyridine Diphosphite Complexes of Rhodium and Iridium
Synthesis and Structural Characterization of Pincer Pyridine Diphosphite Complexes of Rhodium and Iridium
复制标题
铑铱钳吡啶二亚磷酸酯配合物的合成及结构表征
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Pizzano
中科院分区：
文献类型：
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作者：
M. Rubio;A. Suárez;E. Vega;E. Álvarez;J. Díez;M. Gamasa;A. Pizzano
本文报道了一种新的吡啶二亚磷酸酯配体1的合成。由该配体制备了式[MCl（1）]（M = Rh、Ir）的氯化铑和氯化铱配合物。用NaBPh_4和磷烷处理氯化物，产生相应的阳离子磷烷衍生物[M（1）L][BPh_4] [L = PPh_3（Rh，Ir），PPh_2Me（Ir）]。[RhCl（1）]与CNXy（Xy = 2，6-Me 2-C6 H3）和NaBPh 4的类似反应得到单取代配合物[Rh（1）（CNXy）][BPh 4]，而[IrCl（1）]与异腈的反应得到双取代配合物[Ir（1）（L）2][BPh 4]（L = CNBn，CNCy）。[Rh（1）（C2 H4）][BPh 4]是由[RhCl（1）]与NaBPh 4在乙烯下反应得到的，而[Ir（1）（C2 H4）][BPh 4]是由[{IrCl（COE）2}2]与乙烯反应，然后加入1和NaBPh 4得到的。红外光谱分析表明，[M（1）]+片段的π-给体能力很差，因此异腈金属键主要来自异腈的σ-给体。[Rh（1）（PPh 3）][BPh 4]、[Rh（1）（MeCN）][BPh 4]和[Ir（1）（PPh 2 Me）][BPh 4]的X射线晶体学表征显示这些配合物具有正方形平面结构，配体1以钳形方式配位。此外，乙烯衍生物[Rh（1）（C2 H4）][BPh 4]显示出乙烯配体的近平面构象，具有短的C-C距离（1.319 A）。此外，在所有的结构中，无论中性辅助配体的大小，二亚磷酸酯配体表现出内消旋构象。对某些配合物在催化氢化反应中的行为的研究表明，[IrCl（1）]在2-甲基喹啉和2-甲基喹喔啉的还原反应中是一种活性催化剂。
The synthesis of a novel pyridine diphosphite ligand 1 has been described. From this ligand, rhodium– and iridium–chlorido complexes of formula [MCl(1)] (M = Rh, Ir) have been prepared. Chloride abstraction by treatment with NaBPh4 and a phosphane produced the corresponding cationic phosphane derivatives [M(1)L][BPh4] [L = PPh3 (Rh, Ir), PPh2Me (Ir)]. The analogous reaction of [RhCl(1)] with CNXy (Xy = 2,6-Me2-C6H3) and NaBPh4 yielded the monosubstituted complex [Rh(1)(CNXy)][BPh4], whereas the reaction between [IrCl(1)] and isonitriles led to the disubstituted complexes [Ir(1)(L)2][BPh4] (L = CNBn, CNCy). Ethylene compound [Rh(1)(C2H4)][BPh4] was obtained from the reaction of [RhCl(1)] with NaBPh4 under ethylene, whereas [Ir(1)(C2H4)][BPh4] was synthesized by a treatment of [{IrCl(COE)2}2] with ethylene followed by addition of 1 and NaBPh4. An IR analysis of the isocyanide complexes indicates a very poor π-donor ability of the [M(1)]+ fragment, therefore the isocyanide metal bond is mostly due to σ donation from the isocyanide. Characterization by X-ray crystallography of [Rh(1)(PPh3)][BPh4], [Rh(1)(MeCN)][BPh4] and [Ir(1)(PPh2Me)][BPh4] displays a square-planar structure with ligand 1 coordinated in a pincer fashion for these complexes. In addition, the ethylene derivative [Rh(1)(C2H4)][BPh4] shows a near in-plane conformation of the ethylene ligand, with a short C–C distance (1.319 A). Moreover, in all the structures, the diphosphite ligand exhibits a meso conformation irrespective of the size of the neutral ancillary ligand. An examination of the behaviour of some of these complexes in catalytic hydrogenation has shown that [IrCl(1)] is an active catalyst in the reduction of 2-methylquinoline and 2-methylquinoxaline.
影响因子：
15
作者：
Göttker-Schnetmann, I;White, P;Brookhart, M
通讯作者：
Brookhart, M