Organoindium thiolate oligomers: An X-ray structural study

The reaction of R3In (R = methyl, tert-butyl, xylyl) with bis(tricyclohexyl tin) sulfide, 2-methylpropane-2-thiol, 4,6-dimethyl-2-mercaptopyrimidine, c yclopentanethiol, cyclohexanethiol, 2,5-dimethylbenzenethiol, or 2,6-methyl benzenethiol 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 the ir structures have been determined by single-crystal X-ray diffraction tech niques. 2-5 form dimeric species with planar (In-S)(2) cores, 6 forms a tri mer which adopts a skew-boat conformation, 7 forms a trimer with a planar s ix-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 ch air conformation, the first known indium tetramer. Several of the factors o f importance to the structures of these compounds, and especially those whi ch lead to the unusual planar derivative 7, will be discussed.