Chalcogeno-urea Ligands on a Phosphadiazonium Lewis Acceptor: A New Synthetic Approach to Ch-P Bonds (Ch = O, S, Se)

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• 作者：Neil Burford ; Andrew D. Phillips ; Heather A. Spinney ; Katherine N. Robertson ; T. Stanley Cameron ; and Robert McDonald
• 刊名：Inorganic Chemistry
• 出版年：2003
• 出版时间：August 11, 2003
• 年：2003
• 卷：42
• 期：16
• 页码：4949 - 4954
• 全文大小：80K
• 年卷期：v.42,no.16(August 11, 2003)
• ISSN：1520-510X

文摘

The isolation and characterization of the first intermolecular chalcogeno-urea complexes of iminophosphines aredescribed. Trifluoromethylsulfonyloxy(2,4,6-tri-tert-butylphenylimino)phosphine, Mes*NPOTf, reacts quantitatively withchalcogenoimidazolines (ChIm, Ch = O, S, Se) and 1,3-dimethyldiphenylurea (OU) to give Lewis acid-basecomplexes, [Mes*NP·ChIm]OTf and [Mes*NP·OU]OTf. Single crystal X-ray diffraction studies indicate that the closestcontact of the chalcogeno-urea donor occurs at phosphorus in all cases, representing compounds that containexamples of O-P, S-P, and Se-P coordinate bonds. In all complexes, coordination of the ligand causes significantdisplacement of the OTf anion, and the resulting cations [Mes*NP·L]⁺ are best described as complexes of a neutralligand on a phosphadiazonium Lewis acceptor. As such, the complex ions [Mes*NP·L]⁺ are novel examples ofcationic systems containing dicoordinate phosphorus centers. The complexes highlight the potential for electron-rich centers to behave as Lewis acids despite the presence of a lone pair of electrons at the acceptor site.