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Octagallane (tBu3Si)6Ga8 and Its Reduction to (tBu3Si)6Ga82− − On the Existence of Isomeric Gallium Clusters

“…[4] The radical 6 transforms quantitatively at 100°C in heptane into the tetrahedrane 7 [Scheme 2, Equation (c)] which decomposes as a solid at 322°C and in solution at 140°C to metallic gallium [Scheme 2, Equation (e)]. [5] The supersilyl radicals R* · obtained in reactions (c) and (e) dimerize to give superdisilane molecules R* 2 , which at higher temperatures transform via R* · into supersilane R*H. [6] Scheme 2. Decomposition of 5 (the produced supersilyl radical R* stabilizes with formation of R* 2 and/or R*H; R* ϭ SitBu 3 )…”

“…Table 1 Figure 2. View of a molecule of 4 in the crystal (tBu and CH 2 groups excluded for clarity); for bond lengths and angles see Table 1 Eur [5] and R* 8 Ga 18 /R* 8 Ga 22 . [1] On reduction of 3 to 4 some of the GaϪGa bonds lengthen and some shorten, but on average they remain practically constant (mean bond length of 2.64 Å in 3 and 2.61 Å in 4).…”

“…A solution of 5 (0.151 g, 0.130 mmol) in 5 mL of heptane was kept 25 h at 60°C, after which time it had quantitatively decomposed into R*H, [13] R* 2 , [13] 6, [4] 7, [5] and 3 (ratio of 1 H NMR signal areas of the R* groups of molecules R*H, R* 2 , 7, 3 about 1:1:5:3, corresponding to a mol ratio of the compounds of about 4:2:5:2) according to ESR, and 1 H, 13 C and 29 Si NMR spectroscopy. After the removal of all volatile compounds under vacuum and dissolving the residue in 2 mL of benzene, compound 3 (0.115 g, 0.066 mmol, 15%) was obtained after eight days at 8°C as water-and air-sensitive dark-blue crystals.…”

“…After this time, according to the 1 H/ 13 C/ 29 Si NMR spectra, 3 had quantitatively decomposed into R*H, [13] R* 2 , [13] 7, [5] and an unidentified compound R m Ga n (ratio of 1 H NMR signal areas of the R* groups of molecules R*H, R* 2 , 7, R m Ga n about 2:1:10:(4ϩ2), corresponding to a mol ratio of R*H, R* 2 and 7 of about 4:1:5). In addition, an insoluble product was formed (oligogallane ?).…”

Multiply Bonded Germanium, Tin and Lead Compounds

“…Thermal reaction of germirene 123 was performed in the presence of 1/8 molar amount of S 8 to give germanethione Tbt(Dis)Ge=S (124) quantitatively; it was isolated as yellow crystals in a glove box under pure argon (Scheme 48). Similarly, germaneselone Tbt(Dis)Ge=Se (125) and germanetellone Tbt(Dis)Ge=Te (126) were also synthesized quantitatively and isolated as orange-red and blue-green crystals, respectively (Scheme 48) 99,103 . In case of germanethione 124, an alternative synthetic route starting from the corresponding tetrathiagermolane Tbt(Dis)GeS 4 (127) was examined.…”