The interaction of Ga((t)Bu)3 with S8 leads to the formation of a mixture of [((t)Bu)2Ga(mu-SS(t)Bu)]2 (1) and [((t)Bu)2Ga(mu-S(t)Bu)(mu-SS(t)Bu)Ga((t)Bu)2] (2) in a ca. 1:3 molar ratio and trace quantities of [((t)Bu)2Ga(mu-S(t)Bu)]2 (3), which may be prepared directly from (t)BuSH and Ga((t)Bu)3. Compound 1 decomposes in the absence of excess S8 to give 2, while in the presence of S8 the thermolysis of compound 1, 2, or 3 yields the cubane [((t)Bu)GaS]4 (4) and a range of di-tert-butyl polysulfides, (t)BuS(S)(n)S(t)Bu (n = 1-4). Compound 4 may also be prepared by the thermolysis of [((t)Bu)2Ga(mu-SH)]2 (5). Repeated sublimation of 4, at atmospheric pressure, results in its structural rearrangement to the octamer [((t)Bu)GaS]8 (6). The reaction of Ga((t)Bu)3 with Se8 results in the direct formation of the cubane [((t)Bu)GaSe]4 (7). In contrast, the use of metallic Se yields [((t)Bu)2Ga(mu-Se(t)Bu)]2 (8) as the only gallium-containing product; however, prolonged thermolysis of 8 in the presence of excess Se metal also results in the formation of 7. In a similar manner, metallic Te reacts with Ga((t)Bu)3 at ambient temperatures to yield [((t)Bu)2Ga(mu-Te(t)Bu)]2 (9). Thermolysis of 9 in refluxing toluene in the presence of excess Te metal allows for the isolation of the cubane compound [((t)Bu)GaTe]4 (10). The reaction pathway to the formation of the cubane clusters, 4, 7, and 10 is discussed. Compounds 1-10 have been characterized by elemental and thermogravimetric analysis, mass spectrometry, and H-1, C-13, Se-77, and Te-125 NMR spectroscopy. In addition, the structure of 7 has been confirmed by X-ray crystallography. The compound [((t)Bu)GaSe]4 (7) crystallizes in the cubic space group P43nBAR, with a = 17.667 (1) angstrom, Z = 8, 337 observed data, R = 0.047, and R(w) = 0.005.
