Versatile Reactivity of Bridged Pentelidene Complexes toward Secondary and Tertiary Phosphines

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• 作者：Markus Stubenhofer ; Christian Kuntz ; Michael Bodensteiner ; Alexey Y. Timoshkin ; Manfred Scheer
• 刊名：Organometallics
• 出版年：2013
• 出版时间：June 24, 2013
• 年：2013
• 卷：32
• 期：12
• 页码：3521-3528
• 全文大小：385K
• 年卷期：v.32,no.12(June 24, 2013)
• ISSN：1520-6041

文摘

The reaction of the phosphinidene complex [Cp*P{W(CO)₅}₂] (1a) with secondary and tertiary phosphines, respectively, proceeds via W(CO)₅ elimination to form the phosphoranylidene complexes [{W(CO)₅}(Cp*)P-P(H)ⁱPr₂] (2), [{W(CO)₅}(Cp*)P-PMeⁱPr₂] (7), and [{W(CO)₅}(Cp*)P-PEt₃] (9). Other novel types of products, the phosphine-coordinated bridged parent phosphinidene complexes [{W(CO)₅}₂(H)P-PMeⁱPr₂] (6a) and [{W(CO)₅}₂(H)P-PEt₃] (8a), are obtained by elimination of 1,2,3,4-tetramethylfulvene. The latter reaction path is predominantly found for the arsinidene complex [Cp*As{W(CO)₅}₂] (1b) to yield [{W(CO)₅}₂(H)As-PHⁱPr₂] (4) upon reaction with HPⁱPr₂ and, with tertiary phosphines, the products [{W(CO)₅}₂(H)As-PMeⁱPr₂] (6b) and [{W(CO)₅}₂(H)As-PEt₃] (8b). If a secondary phosphine coordinates to a bridged parent pentelidene complex, Cp*H elimination occurs to form either HP[PⁱPr₂{W(CO)₅}]₂ (3) or the phosphine-substituted diarsene complex W(CO)₅[AsPⁱPr₂{W(CO)₅}]₂ (5). Each of the new products has been characterized by X-ray structure analysis, NMR, and mass spectroscopy. In each case as a first step the Lewis acid/base adducts are formed, which was monitored by ³¹P NMR spectroscopy. The different reaction pathways of the electrophilic pentelidene complexes [Cp*E{W(CO)₅}₂] (E = P, As) have been emphasized by extended DFT calculations.