Planar PtPdb>3b> Complexes Stabilized by Three Bridging Silylene Ligands

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• 作者：Dr. Makoto Tanabe ; Ryouhei Yumoto ; Tetsuyuki Yamada ; Tomoko Fukuta ; Tsuyoshi Hoshino ; Prof. Dr. Kohtaro Osakada and Prof. Dr. Tomoaki Tanase
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：23
• 期：6
• 页码：1386-1392
• 全文大小：1703K
• ISSN：1521-3765

文摘

A heterobimetallic PtPdb>3b> complex supported by three bridging diphenylsilylene ligands, [Pt{Pd(dmpe)}b>3b>(μb>3b>-SiPhb>2b>)b>3b>] (<b>1b>, dmpe=1,2-bis(dimethylphosphino)ethane), has been synthesized from mononuclear Pd and Pt complexes. The hexagonal core composed of Pt, Pd, and Si atoms is slightly larger than that of the tetrapalladium complex, [Pd{Pd(dmpe)}b>3b>(μb>3b>-SiPhb>2b>)b>3b>] (<b>2b>). Reaction of PhSiHb>3b> with complex <b>1b> in the presence and absence of Phb>2b>SiHb>2b> results in the formation of a tetranuclear complex with silyl and hydride ligands at the Pt center, [PtH(SiPhb>2b>H){Pd(dmpe)}b>3b>(μb>3b>-SiHPh)b>3b>] (<b>3b>), and an octanuclear complex, [{Pt{Pd(dmpe)}b>3b>(μb>3b>-SiHPh)b>3b>}b>2b>(κ²-dmpe)] (<b>5b>), respectively. Both M−Si (M=Pt, Pd) bond lengths and the ²⁹Si NMR chemical shifts of <b>1b> and <b>2b> are located between those of mononuclear late transition-metal complexes with a silylene ligand and complexes with donor-stabilized silylene ligands. CuI and AgI adducts of <b>1b> and <b>2b>, formulated as [M(μ-M′I){Pd(dmpe)}b>3b>(μb>3b>-SiPhb>2b>)b>3b>] (M=Pt, Pd; M′=Cu, Ag), undergo elimination of CuI (AgI) and regenerate the tetrametallic complexes upon heating or addition of a chelating diphosphine. Elimination of AgI from <b>2-AgIb> occurs more rapidly than elimination of CuI from <b>2-CuIb>, as determined from the results of kinetics experiments.