Halogen photoreductive elimination from metal-metal bonded iridium(II)-gold(II) heterobimetallic complexes.
Halogen photoreductive elimination from metal-metal bonded iridium(II)-gold(II) heterobimetallic complexes.
复制标题
金属-金属键合的铱(II)-金(II)异双金属配合物中的卤素光还原消除。
DOI：
10.1021/ic902590u
复制
发表时间：
2010
影响因子：
4.6
通讯作者：
D. Nocera
中科院分区：
文献类型：
--
作者：
Thomas S. Teets;Daniel A Lutterman;D. Nocera
[Ir（I）Au（I）（dcpm）（2）（CO）X]（PF（6））（dcpm =双（二环己基膦基）甲烷，X = Cl，Br）和[Ir（I）Au（I）（dppm）（2）（CN（t）Bu）（2）]（PF（6））（2）（dppm =双（二苯基膦基）甲烷）的卤素氧化揭示了迄今为止未知的包含Ir（II）Au（II）杂原子核的d（7）-d（9）化合物类别。直接的金属-金属键合从金属间距离的0.2 A收缩是明显的，如通过X射线晶体学测定的。铱-金键形成的物理结果，如实验和计算研究所阐明的，是由具有显著配体-金属电荷转移（LMCT）特征的sigma -> sigma* 跃迁主导的电子结构。因此，这些化合物是非发射性的，但具有光反应性。在卤素陷阱存在下激发Ir（II）Au（II）络合物促使卤素的净光还原消除和双电子还原的Ir（I）Au（I）物质的产生，量子效率约为10%。Ir（II）Au（II）络合物添加到不断增长的d（7）-d（9）杂原子物种库中，其中卤素消除可以由光子驱动。
Halogen oxidation of [Ir(I)Au(I)(dcpm)(2)(CO)X](PF(6)) (dcpm = bis(dicyclohexylphosphino)methane, X = Cl, Br) and [Ir(I)Au(I)(dppm)(2)(CN(t)Bu)(2)](PF(6))(2) (dppm = bis(diphenylphosphino)methane) furnishes the heretofore unknown class of d(7)-d(9) compounds comprising an Ir(II)Au(II) heterobimetallic core. A direct metal-metal bond is evident from a 0.2 A contraction in the intermetallic distance, as determined by X-ray crystallography. The photophysical consequence of iridium-gold bond formation, as elucidated by experimental and computational investigations, is an electronic structure dominated by a sigma --> sigma* transition that possesses significant ligand-to-metal charge transfer (LMCT) character. Accordingly, these compounds are non-emissive but photoreactive. Excitation of Ir(II)Au(II) complexes in the presence of a halogen trap prompts a net photoreductive elimination of halogen and the production of the two-electron reduced Ir(I)Au(I) species with about 10% quantum efficiency. The Ir(II)Au(II) complexes add to a growing library of d(7)-d(9) heterobimetallic species from which halogen elimination may be driven by a photon.