Nuclear magnetic resonance studies of some N′-substituted pyridine-2-carbaldimine adducts of n-butyltrichlorotin(IV) and the molecular structure of n-butyltrichloro(N′-phenylpyridine-2-carbaldimine-NN′)-tin(IV)

Abstract

Six-co-ordinate n-butyltrichlorotin(IV) adducts with some N′-substituted pyridine-2-carbaldimines, SnBuⁿCl₃·C₅H₄N(CHNR)(R = Me, Et, CH₂Ph, Bu^t, Ph, C₆H₄Me-p, or C₆H₄OMe-p), have been isolated. When the substituent (R) on the imine nitrogen atom is Me, Et, or CH₂Ph the adduct exists as a mixture of two isomers in acetonitrile, and when R = Bu^t or the other aryl groups only one species exists. The configuration of these isomers is proposed on the basis of the ¹H chemical shifts of the ligand protons and their spin–spin coupling constants with the tin nuclei. In addition, the molecular structure of the adduct with R = Ph has been determined by single-crystal X-ray diffraction. The triclinic crystal, space group P has cell dimensions a= 8.655(8), b= 13.984(10), c= 8.662(5)Å, α= 102.16(7), β= 104.15(7), γ= 102.97(7)°, and Z= 2. Least-squares refinement of 2 764 independent reflections has given an R factor of 0.027.