Platinum-Mediated Activation of Coordinated Organonitriles by Telluroethers in Tetrahydrofuran: Isolation, Structural Characterization, and Density Functional Theory Analysis of Intermediate Complexes

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• 作者：Siddhartha Kolay ; Amey Wadawale ; Sandeep Nigam ; Mukesh Kumar ; Chiranjib Majumder ; Dasarathi Das ; Vimal K. Jain
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：December 21, 2015
• 年：2015
• 卷：54
• 期：24
• 页码：11741-11750
• 全文大小：678K
• ISSN：1520-510X

文摘

The reactions of [PtCl₂(NCR)₂] with telluroethers (ArAr鈥睺e) in organic solvents have been investigated. The reactions in dichloromethane yield [PtCl₂(TeArAr鈥?₂], while those in tetrahydrofuran (THF) give different products depending on the steric demands of the aryl groups on tellurium, the molarity of the reactants, and the reaction conditions. The reactions between [PtCl₂(PhCN)₂] and TeArAr鈥?in 1:1 molar ratio at room temperature in THF yield several products, like [PtCl₂(TeArAr鈥?₂] (Ar/Ar鈥?= Ph/Ph, o-tol/Mes, Mes/Mes), [PtCl₂(PhCN){NC(O)Ph[TeMes(o-tol)]}], and [PtCl₂{NC(O)Ph(TeMes₂)}₂]. The reaction with TeMes₂ in refluxing THF gave [PtCl₂{NC(Ph)C₄H₇O}{NC(O)Ph(TeMes₂)}] and [PtCl(TeMes₂){Te(Mes)CH₂C₆H₂Me₂}], depending on the duration of heating. Reaction of [PtCl₂(PhCN)₂] with TeArMes afforded [PtCl₂(TeArMes)₂] (Ar = Ph, o-tol, and Mes), the formation of which decreased with increasing steric demand of the Ar group, together with [PtCl₂{NC(O)Ph(TeArMes)}₂]. The telluroether in the latter binds to nitrogen, and tellurium exists in the formal oxidation state of +4 (from XPS). The tellurium in these complexes exhibits secondary interactions with platinum (J(¹⁹⁵Pt鈥?sup>125Te) = 309鈥?47 Hz) and with the carbonyl oxygen. These complexes slowly dissociate in solution to give [PtCl₂(TeMesAr){NC(O)Ph(TeMesAr)}], finally leading to the formation of [PtCl₂(TeMesAr)₂]. Molecular structures of trans-[PtCl₂(PhCN){NC(O)Ph[TeMes(o-tol)]}], trans-[PtCl₂{NC(O)Ph(TeMes₂)}₂], trans-[PtCl₂{NC(Ph)C₄H₇O}{NC(O)Ph(TeMes₂)}], trans-[PtCl₂{NC(O)Ph[TeMes(o-tol)]}₂], trans-[PtCl₂(TeMes₂){NC(O)Ph(TeMes₂)}], trans-[PtCl₂{NC(O)Me(TeMes₂)}₂], and [PtCl(Te-o-tol){NC(O)Ph}₂] have been unambiguously established by single-crystal X-ray diffraction analyses. Density functional theory calculations for some of the complexes were performed, and geometrical parameters are in good agreement with the values obtained from X-ray analyses.