Tetranuclear Organooxotin Cage Compounds Formed with Phosphate and Phosphonate Ligands. < sup > 1 < /sup > a New Class of Organotin Clusters

Abstract

The hydrolysis of methyltin tris(diphenyl phosphate) in ether-methyl cyanide solution yielded a new tetranuclear methyltin cluster, [Me2Sn2(OH)(O2P(OPh)2)3(O3POPh)]2(1). Related derivatives resulted from the condensation reaction of phosphonic acids with n-butylstannonic acid in an acetone solution at room temperature, [R’2Sn2O(O2P(OH)R)4)2: R’ = n-Bu, R = t-Bu (2); R’ = n-Bu, R = Et (3). Also 4 was synthesized (R’ = Me, R = t-Bu). X-ray analysis reveals related cage structures for 1 and 2. Both contain Sn(IV) in a hexacoordinated environment in which the tin atoms are bridged by oxygen or hydroxyl species in addition to bridges by phosphate or phosphonate groups.1H,31P, and119Sn NMR data indicate retention of the solid-state structures in solution. The structural relation between possible cage formulations for 1 and 2 and related tetranuclear crown clusters is described. The crown formulations may be considered hydrolysis products of the cage derivatives. Hydrogen bonding aids in the formation of the cage skeletal arrangement, yielding a pocket potentially useful in clathration. 1 crystallizes in the triclinic space group P ⥘ with a = 13.100 (4) Å, b = 14.372 (4) Å c = 14.958 (5) Å, α = 65.27 (2)°, β = 74.17 (3)°, γ = 87.99 (2)°, and Z = 1. 2 crystallizes in the triclinic space group P ⥘ with a = 12.037 (4) Å, b = 12.712 (2) Å, c = 14.771 (3) Å, α = 98.90 (2)°, β = 104.89 (2)°, γ = 107.41 (2)°, and Z = 1. The final conventional unweighted residuals are 0,024 (1) and 0.050 (2). © 1990, American Chemical Society. All rights reserved.