Synthesis and characterization of triphenyl- and tri-n-butyltin pentafluorobenzoates, -phenylacetates and -cinnamates. X-ray structure determination of tri-n-butyltin pentafluorocinnamate

Article abstract of DOI:10.1016/0022-328X(95)06040-4

A crystal structure analysis of F₅C₆-CH = CH-COOSnBu₃ shows that the compound is polymeric because of the presence of bidentate carboxylate ligands bridging two tin atoms in trans-R₃SnO₂ arrangement. This results in a five-coordinated trigonal-bipyramidal geometry around the tin atom with two apical oxygen atoms and three equatorial butyl groups. Moessbauer and CP-MAS ¹¹⁷Sn NMR data for triphenyl- and tri-n-butyltin pentafluorobenzoates, -phenylacetates and cinnamates, taking the X-ray structure of F₅C₆-CH=CH-COOSnBu₃ as a reference, converge to similar polymeric five-coordinated structures in the solid state. In contrast, ¹³C and ¹¹⁹Sn NMR data in chloroform solution unambiguously indicate tetrahedral four-coordination at tin for all compounds. Failing aromatic ¹³C chemical shift increments and complex ⁿJ(¹³C-¹⁹F) multiplet patterns necessitated recording of 2D ¹⁹F-¹³C HMQC spectra in order to fully characterize the new compounds in solution.