Organoindium thiolate oligomers: An X-ray structural study

The reaction of R3In (R = methyl, tert-butyl, xylyl) with bis(tricyclohexyltin) sulfide, 2-methylpropane-2-thiol, 4,6-dimethyl-2-mercaptopyrimidine, cyclopentanethiol, cyclohexanethiol, 2,5-dimethylbenzenethiol, or 2,6-methylbenzenethiol has yielded seven new indium-sulfur complexes: {m-Xyl(2)In[mu-SSn(C6H11)(3)]}(2) (2), [t-Bu2In(mu-S-C5H9)](2) (3), [t-Bu2In(mu- S-C6H11)](2) (4), {t-Bu2In[mu-S(2,5-Me-2)C6H3]}(2) (5) Me2In(mu-S-t-Bu)](3) (6), {t-Bu2In[mu-S(4,6-Me-2)C4N2H])(3) (7), and [Me2In[mu-S(2,6-Me-2)C6H3])(4) (8) These complexes have been studied by H-1 and C-13 NMR spectroscopy, and their structures have been determined by single-crystal X-ray diffraction techniques. 2-5 form dimeric species with planar (In-S)(2) cores, 6 forms a trimer which adopts a skew-boat conformation, 7 forms a trimer with a planar six-membered (InS)(3) ring with a secondary In-N interaction, giving rise to a pseudo-five-coordinate In atom, and 8 forms a tetramer in an extended chair conformation, the first known indium tetramer. Several of the factors of importance to the structures of these compounds, and especially those which lead to the unusual planar derivative 7, will be discussed.