Studies in mössbauer spectroscopy. Part II. The structures of some organotin halides, and a test of the point-charge model

Mössbauer spectroscopic data are presented for some organotin halides and their halide complexes. These data suggest that the halides R 3 SnX (R = alkyl) are strongly associated in the solid state, with five-coordinate tin atoms. The triphenyltin halides, apart from the flourine, are less strongly associated. The dihalides, R 2 SnX 2 , are also associated, but the structures differ from that of Me 2 SnF 2 . The data are correlated with the point charge model, and it is shown that a parameter, [L], may be ascribed to each ligand, L, which represents the contribution of L to the electric field gradient at the tin nucleus. Self-consistent, empirical values may be assigned to [L]. There is an approximately linear relationship between [L] and the Taft inductive constant σ L * .