Reactions of Dimethyl[tris(trimethylsilyl)methyl]metalanes of Aluminum and Gallium with H 2 S and Elemental Chalcogens – Crystal Structures of [RAl(μ‐S)] 2 ·2 THF, [RGa(μ 3 ‐S)] 4 , [{RAl(μ 3 ‐S)} 3 MeAl(μ 3 ‐S)], [RAlMe(μ‐SeMe)] 2 , and [RGaMe(μ‐TeMe)] 2 [R = C(SiMe 3 ) 3 ]

The reaction of the trialkylalane (Me 3 Si) 3 CAlMe 2 × THF ( 1 ) with H 2 S in toluene at room temperature results in the formation of the dimeric sulfido compound [(Me 3 Si) 3 CAl(μ‐S)] 2 × 2 THF ( 3 ), while the reaction of the homologous gallane (Me 3 Si) 3 CGaMe 2 ( 2 ) with H 2 S under similar conditions affords the heterocubane [(Me 3 Si) 3 CGa(μ 3 ‐S)] 4 ( 4 ). Heating of compound 3 in vacuo gives a mixture of the symmetrically substituted [(Me 3 Si) 3 CAl(μ 3 ‐S)] 4 ( 5 ) and the unsymmetrically substituted heterocubane [{(Me 3 Si) 3 CAl(μ 3 ‐S)} 3 MeAl(μ 3 ‐S)] ( 6 ). Reaction of the trialkylmetalanes 1 and 2 with elemental selenium in refluxing toluene results in the formation of the corresponding selenolates [(Me 3 Si) 3 CMMe(μ‐SeMe)] 2 ( 7 , M = Al; 8 , M = Ga). The compounds exhibit a high thermal stability and can not be converted to the corresponding selenides [(Me 3 Si) 3 CM(μ 3 ‐Se)] n (M = Al, Ga) upon heating. In contrast, the trialkylalane 1 does not react with tellurium metal in refluxing toluene at all, while the trialkylgallane 2 affords the tellurolate [(Me 3 Si) 3 CGaMe(μ‐TeMe)] 2 ( 9 ) under similar conditions. Compounds 3–9 have been characterized by 1 H‐ and 29 Si‐NMR, mass, and IR spectroscopy. Furthermore, the molecular structures of compounds 3 · C 6 H 6 , 4 · 1.5 C 6 H 6 , 6 , 7 · C 6 H 6 and 9 have been determined by X‐ray crystallography.