Cubic, Butterfly, and Oxygen-Capped Clusters of n-Butyloxotin Phosphinates. A New Class of Organotin Compounds

Abstract

Reaction of n-butylstannoic acid with the phosphinic acids, R5PO2H, where R = tert-butyl, benzyl, and cyclohexyl, has led to new types of structural forms for hexacoordinated tin: two cubic clusters, [n-BuSn(O)O2P(NBu)2]4(1) and [n-BuSn(O)O2P(CH2Ph)2]4(2), respectively, and a “butterfly” cluster, [n-BuSn(OH)(O2P(C6H11)2)2]2(3). Interesting transformations of cubes and the butterfly derivative yield oxygen-capped cluster formulations, [(R'Sn(OH)O2PR2)3O] [R2PO2], where R' = n-Bu and R = C6H11 or CH2Ph, 119Sn and 31P NMR show these structural characteristics in solution. The 119Sn chemical shift correlates with increasing cluster complexity, i.e., with an increasing ligand to tin component in the various formulations discovered so far. 1 crystallizes in the triclinic space group PĪ with a = 13.616 (4) Å, b = 13.857 (3) Å, c = 20.544 (4) Å, α= 79.95 (2)°, β= 69.16 (2)°, γ= 71.15 (2)°, and Z = 2. 2 crystallizes in the tetragonal space group P421C with a = 17.630 (4) A, c = 11.825 (3) A, and Z = 2. 3 crystallizes in the triclinic space group PĪ with a = 10.758 (3) Å, b = 12.133 (4) Å, c = 13.038 (4) Å, α= 79.93 (2)°, β= 73.72 (2)°, γ= 89.53 (2)°, and Z = 1. The conventional unweighted residuals were 0.038 (1), 0.042 (2), and 0.042 (3). © 1988, American Chemical Society. All rights reserved.