Reaction of LiArMe6LiArMe6 (ArMe6ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) with indium(I)chloride yields three m-terphenyl stabilized mixed-valent organoindium subhalides

Indium(I)chloride reacts with LiArMe6LiArMe6 (ArMe6ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) in THF to give three new mixed-valent organoindium subhalides. While the 1:1 reaction of InCl with LiArMe6LiArMe6 yields the known metal-rich cluster In8(ArMe6ArMe6)4 (1), the use of freshly prepared LiArMe6LiArMe6 led to incorporation of iodide, derived from the synthesis of LiArMe6LiArMe6, into the structures, to afford In4(ArMe6ArMe6)4I2 (2) along with minor amounts of In3(ArMe6ArMe6)3I2 (3). When the same reaction was performed in 4:3 stoichiometry, the mixed-halide compound In3(ArMe6ArMe6)3ClI (4) was obtained. Further increasing the chloride:aryl ligand ratio resulted in the formation of the known mixed-halide species In4(ArMe6ArMe6)4Cl2I2 that can also be obtained from the reaction of InCl with in situ   prepared LiArMe6LiArMe6 in toluene. The new compounds 2 and 4 were characterized in the solid state by X-ray crystallography and IR spectroscopy, and in solution by UV/Vis and 1H/13C{1H} NMR spectroscopies. The structural characterization of 2 and 4 was supported by electronic structure calculations at the density functional level of theory which were also performed to rationalize the cluster-type bonding in 1.

The synthesis and characterization of two new mixed-valent indium subhalides is presented. Reactions of LiArMe6LiArMe6 with varying amounts of In(I)Cl yield products incorporating different halides depending on the reaction conditions. DFT calculations were performed to investigate the electronic structures of the compounds as well as that of the cluster In8(ArMe6ArMe6)4.Figure optionsDownload as PowerPoint slide