Backbone modified small bite-angle diphosphines: Synthesis, structure, and DFT evaluation of the thermal activation products based on Os₃(CO)₁₀{渭-Ph₂PC(Me)₂PPh₂}

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• 作者：Jagodish C. Sarker ; Arun K. Raha ; Shishir Ghosh ; Graeme Hogarth ; Shariff E. Kabir ; Michael G. Richmond
• 关键词：Triosmium cluster ; Diphosphine ligand ; P&ndash ; C bond cleavage ; DFT ; X-ray crystallography
• 刊名：Journal of Organometallic Chemistry
• 出版年：15 January, 2014
• 年：2014
• 卷：750
• 期：Complete
• 页码：49-58
• 全文大小：1437 K

文摘

Addition of 2,2'-bis(diphenylphosphino)propane, Ph₂PC(Me)₂PPh₂ (dppmMe₂), to Os₃(CO)₁₀(MeCN)₂ at room temperature affords Os₃(CO)₁₀{渭-Ph₂PC(Me)₂PPh₂} (1-Me₂), whose X-ray diffraction has been established and found to contain a bridging diphosphine ligand. Heating 1-Me₂ in toluene results in the formation of the expected orthometalated addition product Os₃(CO)₈{渭₃-Ph₂PC(Me)₂P(Ph)C₆H₄}(渭-H) (2-Me₂) in only trace amounts, with the face-capped cluster Os₃(CO)₉{渭₃-PhPC(Me)₂P(Ph)C₆H₄} (3-Me₂) formed as the major product as a result of elimination of benzene. The conversion of 1-Me₂ to 2-Me₂ has been investigated by density functional theory (DFT) calculations and the potential energy surface has been mapped out. The observed reactivity in the dppmMe₂-substituted cluster 1-Me₂ is compared with the related dppmH₂- and dppmHMe-substituted triosmium complexes.