# The solvation of trimethylchlorostannane in non-aqueous solution

Linert, Wolfgang (1990) The solvation of trimethylchlorostannane in non-aqueous solution. Accademia Peloritana dei Pericolanti Classe FF.MM.NN., 68. pp. 19-39.

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The molecular structures of trimethylchlorostannane in various donor solvents have been investigated by far IR spectroscopy. The absorption frequency associated with the Sn-Cl stretching vibration is found linearly related to the solvent donor number. The Cl-Sn-C angles of the complex species in solution were evaluated fom the ratio of the absorption intensities of the symmetrical and the asymmetrical Sn-C stretching vibrations and are also found to be related to the solvent donor number. A continuous set of molecular geometries between tetrahedral and trigonal bipyramidal arrangement is found, the bypyramidal form being approached more closely as the solvent DN is increased. The results obtained in this way are found in agreement with the results obtained by X-ray and electron diffraction and can be compared with results from $^1^1^9Sn$ and $^1H$ NMR-spectroscopy. It has further been found that alcohols appear to interact not only as donors through the oxygen atoms, but also as acceptors with formation of O-H... Cl bonds. The experimental results are closely related to structural changes and charge distributions as calculated by means of the semi-empirical MNDO method. The charge distribution and the C-Sn-Cl angle $(^\alpha CSnCl)$ react sensitive to changes of the distance between the tin atom and the donor. For exampie the distance between $Cl^-$ acting as donor towards the Sn, $i.e.d_C_l_\longrightarrow_S_n$ has been varied to calculate the changes in atomic charges,$^\alpha_C-_S_n-_C_l$ and the total energies for the adduct $(CH_3)_3SnCl\bullet Cl^-$. With decreasing $^d_C_l_\longrightarrow_S_n$ the positive charge at the tin atom is increased, the charge at the originally bound chlorine atom is shifted to more negative values. The total energy is decreased until it reaches its minimum at equal $^d_C_l_\longrightarrow_S_n$ and $^d_S_n_-_C_l$ distances.