HYDROLYSIS PATHWAY LEADING TO THE FORMATION OF NOVEL OXO- AND HALO-BRIDGED TIN(IV) LADDER COMPOUNDS. THE MOLECULAR STRUCTURE OF THE DIMERIC DISTANNOXANES [Ph2(CI)SnOSnPh2(OH)]2.2(CH3)2CO AND [Ph2(CI)SnOSnPh2(CI]2

Abstract

Abstract Acid-base adduct formation occurs in benzene solutions of Ph2SnCl2 with quinuclidine, Dabco, and acridine as ligands. By use of the latter base, the dichlorodistannoxane [Ph2CISnOSnPh2Cl]2 (6) also was isolated. In more polar solvents, hydrolysis reactions of Ph2SnCl2 occur more readily, leading to dimeric distannoxanes. The hydroxystannoxane [Ph2C1SnOSnPh2OH]2.2(CH3)2CO (5) is isolated from the reaction of Ph2SnCl2 and quinuclidine in acetonitrile solution. It is also obtained by the analogous reaction of Dabco in acetone. Further characterized from these reactions were anionic complexes [Ph2SnC14][base H]2 (base = quinuclidine, Dabco, or acridine). The isolation and structural characterization of successive members in the hydrolysis lead to a mechanism of formation of the dimeric distannoxanes 5 and 6. X-ray analysis shows they both possess “ladder” structures with tin atoms in trigonal-bipyramidal conformations. This is the first structural study of distannoxanes containing directly bonded aryl groups. 5 crystallizes in the monoclinic space group P21/n with a = 11.758 (2) Å, b = 19.327 (3) Å, c = 11.649 (1) Å, β= 92.87 (1)°, and Z = 2. The structure was refined to R = 0.028 and Rw = 0.039. For 6, the monoclinic space group P211c was obtained with a = 10.284 (2) Å, b = 10.513 (3) Å, c = 22.143 (4) Å, β = 100.75 (2)°, and Z = 2. The structure was refined to R = 0.023 and Rw = 0.034.