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 2 In(diox) 2 CH 2 Br, reacts with triphenylphosphine oxide, triphenylphosphine sulfide and benzyl sulfide to produce the compounds Br 2 In[OP(C 6 H 5 ) 3 ] 2 CH 2 Br and Br 3 InCH 2 L (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 2 C δ−  δ+ S(CH 2 C 6 H 5 ) 2 , and a triphenylphosphonium-sulfur methylide ligand, δ− CH 2 S δ+ P(C 6 H 5 ) 3 , in the Br 3 InCH 2 L compounds. Mass spectra and thermal decomposition studies establish that Br 3 InCH 2 S(CH 2 C 6 H 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 6 H 5 CH 2 carbon to yield benzyl bromide and benzyl-methyl-sulfide.