[Ru(xantsil)(CO)(η6-toluene)]: Synthon for a Highly Unsaturated Ruthenium(II) Complex through Facile Dissociation of the Toluene Ligand [xantsil = (9,9-dimethylxanthene-4,5-diyl)bis(d

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• 作者：Masaaki Okazaki ; Nobukazu Yamahira ; Jim Josephus Gabrillo Minglana ; Takashi Komuro ; Hiroshi Ogino ; Hiromi Tobita
• 刊名：Organometallics
• 出版年：2008
• 出版时间：March 10, 2008
• 年：2008
• 卷：27
• 期：5
• 页码：918 - 926
• 全文大小：398K
• 年卷期：v.27,no.5(March 10, 2008)
• ISSN：1520-6041

文摘

The reactions of [Ru(xantsil)(CO)(η⁶-C₆H₅CH₃)] [1a, xantsil = (9,9-dimethylxanthene-4,5-diyl)bis(dimethylsilyl))] with some electron-donating molecules were reported. When 1a was dissolved in benzene, benzene replaced the η⁶-toluene ligand easily at room temperature to give [Ru(xantsil)(CO)(η⁶-C₆H₆)] (1b). The η⁶-toluene ligand was also substituted by sterically less demanding two-electron donors smoothly at room temperature to afford [Ru(xantsil)(CO)L₃] (L = CH₃CN (2), ^tBuNC (3), and PMe₃ (4)). The X-ray diffraction studies revealed that they take a typical octahedral geometry, in which the xantsil ligand is coordinated to the Ru(II) center in κ²(Si,Si) fashion. Reactions of 1a with sterically demanding phosphines gave [Ru(xantsil)(CO)(PR₃)] (R = ⁱPr (5) and Cy (6)). According to the X-ray diffraction study, complex 6 takes a square-pyramidal geometry, in which the xantsil ligand is bound to the Ru(II) center in κ³(Si,Si,O) fashion and one of the silyl groups occupies the apical position. The coordinatively unsaturated Ru(II) center is slightly stabilized by the agostic interaction by the C−H bonds in PCy₃ [Ru···H: 2.89 and 3.06 Å]. The highly coordinatively unsaturated nature in 6 was indicated by the reaction with carbon monoxide molecules to give [Ru(xantsil)(CO)₃(PCy₃)] (7) at room temperature. The typical octahedral geometry with the κ²(Si,Si)-xantsil ligand was established by the X-ray diffraction study.