Preparation, crystal structure determination, and properties of adducts of halogenomethyl compounds of indium with Group 16 donors

Abstract

The bis-1,4-dioxane (diox) adduct of bromomethyl-dibromo-indium(III), Br 2In(diox) 2CH 2Br, reacts with triphenylphosphine oxide, triphenylphosphine sulfide and benzyl sulfide to produce the compounds Br 2In[OP(C 6H 5) 3] 2CH 2Br and Br 3InCH 2L (L=benzyl sulfide, triphenylphosphine sulfide). The crystal structures of these new organoindium compounds have been solved by X-ray diffraction methods. The structural results are compared with those for related organoindium compounds. Quantum mechanical calculations, by the PM3 method, satisfactorily predict the measured bond distances and angles in all compounds, and hence furnish reliable net atomic charge maps, which demonstrate the presence of a sulfur ylid ligand, H 2C δ− δ+S(CH 2C 6H 5) 2, and a triphenylphosphonium-sulfur methylide ligand, δ−CH 2S δ+P(C 6H 5) 3, in the Br 3InCH 2L compounds. Mass spectra and thermal decomposition studies establish that Br 3InCH 2S(CH 2C 6H 5) 2 decomposes via an intramolecular nucleophilic attack of a bromide ligand, either to the InCH 2 carbon atom to produce benzyl sulfide, or to the C 6H 5CH 2 carbon to yield benzyl bromide and benzyl-methyl-sulfide.