PNP-Ligated Heterometallic Rare-Earth/Ruthenium Hydride Complexes Bearing Phosphinophenyl and Phosphinomethyl Bridging Ligands

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• 作者：Wylie W. N. O ; Xiaohui Kang ; Yi Luo ; Zhaomin Hou
• 刊名：Organometallics
• 出版年：2014
• 出版时间：February 24, 2014
• 年：2014
• 卷：33
• 期：4
• 页码：1030-1043
• 全文大小：629K
• 年卷期：v.33,no.4(February 24, 2014)
• ISSN：1520-6041

文摘

The reaction of rare-earth bis(alkyl) complexes containing a bis(phosphinophenyl)amido pincer (PNP), LnPNP_iPr(CH₂SiMe₃)₂ (1-Ln, Ln = Y, Ho, Dy), with ruthenium trihydride phosphine complexes, Ru(C₅Me₅)H₃PPh₃ and Ru(C₅Me₅)H₃PPh₂Me, gave the corresponding bimetallic Ln/Ru complexes bearing two hydride ligands and a bridging phosphinophenyl (渭-C₆H₄PPh₂-魏P:魏C¹, 2a-Ln) or a bridging phosphinomethyl ligand (渭-CH₂PPh₂-魏P:魏C, 2b-Ln), respectively. Reaction of 2a-Y with CO gas at 1 atm and at 20 掳C in toluene-d₈ afforded the complex 3a-Y, which bears a bridging pseudooxymethylene ligand (渭-OCH(o-C₆H₄)PPh₂-魏P:魏O) and a bridging hydride ligand on the Y/Ru centers. Computational studies by the DFT method suggested that 3a-Y was formed in two steps: first the coordination of CO (螖G(B3PW91) = 22.9; 螖G(M06) = 14.9 kcal/mol) and migratory insertion of the Y鈥揅₆H₄ group (螖G(B3PW91) = 13.3; 螖G(M06) = 16.7 kcal/mol), followed by a rapid intramolecular hydride migration to the resulting acyl group. Complex 2b-Y reacted with organic nitriles (tBuCN, CH₃CN, PhCN), an aldimine (PhNCHPh), an isonitrile (tBuNC), and group IX transition-metal carbonyls (M(C₅Me₅)(CO)₂, M = Rh, Ir) via insertion of the reactive Y鈥揅H₂ group into the unsaturated bond. These reactions afforded complexes with new ligand scaffolds, including a bridging alkylideneamidophosphine (4b-Y), an amidophosphine (7b-Y), an 畏²-iminoacylphosphine (8b-Y), and oxycarbenephosphine (9b-Y and 10b-Y) ligands at the binuclear Y/Ru core. All of these reaction products were structurally characterized by X-ray crystallography, NMR spectroscopy, and elemental analyses.