Molecular dynamics of adducts of organotin(IV) and tin(IV) chlorides with NN′-ethylenebis(salicylideneimine) studied by temperature-dependent Mössbauer spectroscopy

Abstract

Lattice dynamics studies have been carried out on the solid-state polymers (SnR_nCl_4–n·H₂salen)_x(H₂salen =NN′-ethylenebis(salicylideneimine); n= 2, R = Me or Ph; n= 1, R = Me, Buⁿ, n-octyl, or Ph; n= 0), as well as on the monomeric complex SnMe₂(salen), by temperature-dependent Mössbauer spectroscopy. The functions In A(T), In f_a(T), and 〈x²〉(T) are linear for adducts with n= 0–2 and R = Me or Ph, but are perceptibly nonlinear for the remaining compounds, suggesting motional anharmonicity of ¹¹⁹Sn atoms in the latter. Compounds characterized by linear functions form two distinct homologous series (n= 2, n= 0 or 1) where a general decrease of the parameters θ_D and [graphic omitted]_D takes place in parallel to an increase of the vibrating mass. The results are discussed in relation to the vibrating mass model, and to previous investigations. The characteristics of the anharmonic derivatives are tentatively interpreted in terms of progressive structural changes to to form monomers.