Synthesis and characterization of perhalophenyltin derivatives. Study of their reactivity toward phosphine gold(I) chlorides

Resumen

The (perhalophenyl)tin derivatives [SnR4] (1-3) and [SnR 3Cl] (4-6) (R = C6F5, C6F 3Cl2, C6Cl5) were prepared from SnCl4 and LiR or [SnR4] in the appropriate molar ratio, while the dinuclear complexes [SnR3]2 (7-9) were obtained by treatment of [SnR3Cl] with potassium under toluene reflux. Complexes 2, 6·0.5toluene and 7 were structurally characterized, the latter displaying a Sn-Sn bond of 2.808(7) , which indicates a strong tin-tin bond with covalent character in solid state. The hexaaryldistannanes 7-9 undergo transmetallation reactions with gold(I) derivatives, such as [AuCl(PPh 3)] or [(AuCl)2(μ-dppm)], affording the neutral species [AuR(PPh3)] (10-12) or [(AuR)2(μ-dppm)] (13-15) or the ionic product [Au3Cl2(μ-dppm)2][Sn(C 6F5)3Cl2] (16). The crystal structures of 14·CH2Cl2, 15 and 16·2CH 2Cl2 were determined by X-ray diffraction, the latter showing a Au3 nearly equilateral triangular core in the cation with gold-gold contacts of 3.128(7) and 3.227(12) . The main difference between the molecular structures of 14·CH2Cl2 and 15 (both of them displaying intramolecular gold-gold contacts of 3.142(6) and 3.160(4) , respectively) is the presence of an intermolecular Au⋯Au interaction of 3.2126(8) in the case of the C6F3Cl2 complex that gives rise to a tetranuclear unit. © 2010 Elsevier B.V. All rights reserved.