Cubic, butterfly, and oxygen-capped clusters of n-butyloxotin phosphinates. A new class of organotin compounds1, 2

Abstract

Reaction of n-butylstannoic acid with the phosphinic acids, R2PO2H, where R = tert-butyl, benzyl, and eyclohexyl, has led to new types of structural forms for hexacoordinated tin: two cubic clusters, [n-BuSn(O)O2P(t-Bu),]4 (1) and [n-BuSn(O)O2P(CH2Ph)2]4 (2), respectively, and a "butterfly" cluster, [n-BuSn(OH)(O2P(C6H11)2]2 (3). Interesting transformations of cubes and the butterfly derivative yield oxygen-capped cluster formulations, [(R'Sn(OH)O2PR2), O][R2PO2], where R' = n-Bu and R = C6H11or CH2Ph. 119 Sn and 31 P NMR show these structural characteristics in solution. The 119 Sn 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 P1 with a = 13. 616 (4) Å, b = 13. 857 (3) Å, c = 20. 544 (4) Å, a = 79. 95 (2)°, β = 69.16 (2)°, λ = 71. 15 (2)°, and Z =2. 2 crystallizes in the tetragonal space group P421c with a = 17. 630 (4) Å, c = 11. 825 (3) Å, and Z = 2. 3 crystallizes in the triclinic space group P1 with a = 10. 758 (3) Å, b = 12. 133 (4) Å, c = 13. 038 (4) Å, α = 79. 93 (2)°, β = 73. 72 (2)°, λ = 89. 53 (2)°, and Z = 1. The conventional unweighted residuals were 0.038 (1), 0.042 (2), and 0.042 (3). © 1995, Taylor & Francis Group, LLC. All rights reserved.