由螯合吡啶基-吡咯化物配体支撑的高氧化态铑和铱双（硅烷基）二氢配合物。

High oxidation state rhodium and iridium bis(silyl)dihydride complexes supported by a chelating pyridyl-pyrrolide ligand.

作者信息

McBee Jennifer L, Escalada Jose, Tilley T Don

机构信息

Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA.

出版信息

J Am Chem Soc. 2009 Sep 9;131(35):12703-13. doi: 10.1021/ja9035169.

DOI:10.1021/ja9035169

PMID:19681602

Abstract

New rhodium and iridium complexes containing the bidentate ligand 3,5-diphenyl-2-(2-pyridyl)pyrrolide (PyPyr) were prepared. The bis(ethylene) complex (PyPyr)Rh(C(2)H(4))(2) (3) reacted with HSiEt(3), HSiPh(3), and HSi(t)BuPh(2) to produce the 16-electron Rh(V) bis(silyl)dihydrides (PyPyr)Rh(H)(2)(SiEt(3))(2) (8), (PyPyr)Rh(H)(2)(SiPh(3))(2) (9), and (PyPyr)Rh(H)(2)(Si(t)BuPh(2))(2) (10), respectively. The analogous Ir(V) bis(silyl)dihyride (PyPyr)Ir(H)(2)(SiPh(3))(2) (11) has also been synthesized. X-ray crystallography reveals that 9-11 adopt a coordination geometry best described as a bicapped tetrahedron. Silane elimination from 9 and 10 occurred in the presence of either HSiEt(3) or PPh(3). Mechanistic studies of the silane exchange process involving 10 and free HSiEt(3) (to give 8) indicate that this process occurs by rate-limiting reductive elimination of HSi(t)BuPh(2) from 10 to generate a 14-electron Rh(III) intermediate of the type (PyPyr)Rh(H)(Si(t)BuPh(2)).

摘要

制备了含有双齿配体3,5-二苯基-2-(2-吡啶基)吡咯烷（PyPyr）的新型铑和铱配合物。双(乙烯)配合物(PyPyr)Rh(C₂H₄)₂(3)与HSiEt₃、HSiPh₃和HSi(t)BuPh₂反应，分别生成16电子的铑(V)双(硅基)二氢化物(PyPyr)Rh(H)₂(SiEt₃)₂(8)、(PyPyr)Rh(H)₂(SiPh₃)₂(9)和(PyPyr)Rh(H)₂(Si(t)BuPh₂)₂(10)。类似的铱(V)双(硅基)二氢化物(PyPyr)Ir(H)₂(SiPh₃)₂(11)也已合成。X射线晶体学表明，9 - 11采用一种最好描述为双帽四面体的配位几何结构。在HSiEt₃或PPh₃存在下，9和10发生硅烷消除反应。对涉及10和游离HSiEt₃（生成8）的硅烷交换过程的机理研究表明，该过程通过从10中限速还原消除HSi(t)BuPh₂以生成(PyPyr)Rh(H)(Si(t)BuPh₂)类型的14电子铑(III)中间体而发生。