Crystal structure of trichloroacetatotrivinyltin and Mössbauer spectroscopic characterization of trivinyl- and divinyl-n-butyltin carboxylates

Abstract

The structure of the title compound has been determined by X-ray analysis. It consists of Sn(CHCH₂)₃(O₂CCCl₃) units linked by syn–anti trichloroacetate bridges giving five-co-ordinate tin atoms. The compound crystallizes in space group I2/a with a= 16.686(9), b= 10.267(6), c= 15.866(9)Å, β= 107.08(8), and Z= 8. A comparison of these structural data with those available for SnMe₃(O₂CMe), SnMe₃(O₂CCF₃), and Sn(CH₂Ph)₃(O₂CMe) reveals that distortions of the SnC₃ group and the asymmetry of the two Sn–O distances are in the order benzyl > vinyl > methyl. The influence of the vinyl groups around the tin atom has also been examined by Mössbauer spectroscopy. The Mössbauer parameters of two series of compounds, Sn(CHCH₂)₃(O₂CR′) and SnBu(CHCH₂)₂(O₂CR′)(R′= Me, CH₂Br, CH₂Cl, CHCl₂, CCl₃, or CF₃), have been determined. The quadrupole-splitting data, compared with those available for other series of organotin carboxylates having a trigonal-bipyramidal geometry, are consistent with the structural information. These values decrease with increasing distortion and asymmetry of the lattice.