A new system in organooxotin cluster chemistry incorporating inorganic and organic spacers between two ladders each containing five tin atoms.

Hydrolysis of dibenzyltin dichloride in ethanol has been found to give an unprecedented carbonate anion (CO(3) (2-))-bridged double-ladder organooxotin cluster, (R(2)SnO)(3)(R(2)SnOH)(2)(CO(3)) (1, R = C(6)H(5)CH(2)), with five tin atoms in each ladder. With the aim of obtaining organooxotin clusters with large cavities suitable for host-guest chemistry, we used 1,1'-ferrocenedicarboxylic acid (H(2)L(a)) and hexanedioic acid (H(2)L(b)) to replace the carbonate anions (CO(3) (2-)), and thereby clusters (R(2)SnO)(3)(R(2)SnOH)(2)L(a) (2) and (R(2)SnO)(3)(R(2)SnOH)(2)L(b) (3) were obtained. When 1 was treated with benzoic acid (HL(c)) in different stoichiometric ratios (1:4, 1:10), ladder cluster (R(2)SnO)(3)(R(2)SnOH)(2)(L(c))(2) (4) and drum cluster RSn(O)L(c) (5) were obtained. Through the hydrolysis of Cy(2)SnCl(2) (Cy = C(6)H(11)) and (C(6)H(5)CH(2))(2)SnCl(2), two interesting ethanolate-modified clusters Cy(2)(C(2)H(5)O)SnOSn(C(2)H(5)O)Cy(2) (6) and (R(2)SnO)(3)(R(2)SnOH)(R(2)SnOC(2)H(5))(CO(3)) (7) were obtained. All the tin atoms in these ladder clusters are five-coordinate surrounded by two alkyl groups and three O atoms, and have distorted trigonal-bipyramidal coordination environments with two carbon atoms and one O atom in the equatorial positions and two O atoms in the axial positions. The structures of all these compounds have been established by single-crystal X-ray diffraction analyses.