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• 作者：Claudia Cavazza ; Fabrizia Fabrizi de Biani ; Tiziana Funaioli ; Piero Leoni ; Fabio Marchetti ; Lorella Marchetti ; Piero Zanello
• 刊名：Inorganic Chemistry
• 出版年：2009
• 出版时间：February 16, 2009
• 年：2009
• 卷：48
• 期：4
• 页码：1385-1397
• 全文大小：373K
• 年卷期：v.48,no.4(February 16, 2009)
• ISSN：1520-510X

文摘

Useful synthons containing the tribridged triangular unit {Pt₃} = [Pt₃(μ-P^tBu₂)₃]⁺ were prepared starting from the known tricarbonyl derivative [{Pt₃}(CO)₃]Z, [(1⁺)Z, Z = CF₃SO₃⁻]. This was easily converted into the monohalides {Pt₃}(CO)₂X [2, X = Cl; 3, X = Br; 4, X = I], by reaction with the appropriate halide salt. The coupling reaction between 2 and terminal alkynes in the presence of CuI afforded in good yields the σ-alkynyl derivatives {Pt₃}(CO)₂(CC-R) [6, R = SiMe₃; 7, R = CC-SiMe₃; 8, R = C₆H₅; 9, R = C₆H₄-4-Br; 10, R = C₆H₄-4-CCH; 11, R = 2-C₄H₂S-5-CCH; 12, R = 9-C₁₄H₈-10-CCH], while desilylation of 6 or 7 with TBAF/THF gave, respectively, the derivatives 13 (R = H) and 14 (R = CCH). The stepwise elongation of the arylalkynyl chain was obtained by the Sonogashira coupling of 10 with an excess of 1,4-diiodobenzene, which produced 15 (R = C₆H₄-4-CC-C₆H₄-4-I), and by coupling the latter with an excess of 1,4-diethynylbenzene, which formed 16 (R = [C₆H₄-4-CC]₃H). Branched synthons were obtained by substitution of the carbonyl ligands with functional isocyanides; the reaction of an excess of CN-C₆H₄-4-R (R = I, CCH) with {Pt₃}(CO)₂H, 5, or with complex (1⁺)Z afforded, respectively, {Pt₃}(CN-C₆H₄-4-I)₂H, 17, or [{Pt₃}(CN-C₆H₄-4-R)₃]Z [(18⁺)Z, R = I; (19⁺)Z, R = CCH]. The crystal structures of complexes 2, 8, and 9 were established by X-ray diffraction studies. The electrochemical characterization of representative examples of the clusters prepared in this work shows that all clusters are characterized by the presence of two oxidations; an analysis of ligands’ effects on the redox processes is also included.