Anions of Tridentate SPS Ligands: Syntheses, X-ray Structures and DFT Calculations

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• 作者：Marjolaine Doux ; Pierre Thu&eacute ; ry ; Matthias Blug ; Louis Ricard ; Pascal Le Floch ; Th&eacute ; rè ; se Arliguie ; Nicolas M&eacute ; zailles
• 刊名：Organometallics
• 出版年：2007
• 出版时间：November 5, 2007
• 年：2007
• 卷：26
• 期：23
• 页码：5643 - 5653
• 全文大小：379K
• 年卷期：v.26,no.23(November 5, 2007)
• ISSN：1520-6041

文摘

Reaction of 2,6-bis(diphenylphosphine sulfide)-3,5-diphenylphosphinine (SPS) (1) with alkyllithiumreagents (MeLi, n-BuLi, Li-methyl pyridine) led to formation of the stable lithium salts [Li(THF)₂][SPS^(Me)] (2), [Li(THF)₂][SPS^(n-Bu)] (3), and [Li(THF)₂][SPS^(CH2Py)] (12) by a nucleophilic attack on thecentral phosphorus atom of the phosphinine ring, whereas treatment of 1 with t-BuLi led to the intermediateformation of [Li(THF)₂][SPS^(t-Bu)] (4) followed by elimination of isobutene and formation of [Li(THF)₂][SPS^(H)] (5). By addition of optically pure lithium (-)-mentholate or (-)-menthyl Grignard reagent to 1the chiral derivatives [Li(THF)₂][SPS^(OMen)] (6) and [Li(THF)₂][SPS^(Men)] (9) were obtained, respectively.The potassium salt of the anionic SPS pincer ligand [K(THF)₂][SPS^(Me)] (10) was isolated from a saltexchange reaction of 2 with t-BuOK in diethyl ether. Coordination of BH₃ to the central phosphorusatom in compound [K([18]crown-6)THF)][SPS^(Me)·BH₃] (11) confirmed the phosphine character of thehypervalent ⁴ phosphorus atom. The X-ray crystal structures of compounds 2a, 2b, 10, and 12 revealthe flexibility of the [SPS^(Me)] anion ligand. Finally, the difference in the electronic properties and structuralfeatures of compounds 2a and 2b were investigated by means of DFT calculations and a NBO analysis.