Chalcogenido-Dimethylgallates and -Indates DMPyr [Me M(μ -E)] (M=Ga, In; E=S, Se): Building Blocks for Higher and Lower Order Chalcogenidoindates.

Metalation of the anions in the ionic liquids DMPyr[SH] and DMPyr[SeH] (DMPyr=1,1-dimethylpyrrolidinium) by trimethylgallium and trimethylindium is investigated. The reaction proceeds via pre-coordination of [EH] , methane elimination and formation of an unprecedented series of chalcogenido metalates DMPyr [Me M(μ -E)] (M=Ga, In; E=S, Se). These show the presences of dinuclear dianions with four-membered ring structures displaying highly nucleophilic bridging chalcogenide ligands in their crystallographically determined molecular structures. Some representative reactions of these building blocks with amphoteric electrophiles were studied: Addition of two equivalents of E(SiMe ) (E=S, Se) to the indates DMPyr [Me In(μ -S)] and DMPyr [Me In(μ -Se)] leads to a cleavage of the ring, E silylation and formation of mononuclear, monoanionic indates DMPyr[Me In(SSiMe ) ], DMPyr[Me In(SeSiMe ) ], and even a mixed sulfido-selenido dimethylindate DMPyr[Me In(SSiMe )(SeSiMe )]. Reaction of DMPyr [Me In(μ -S)] with two equivalents of Lewis acid Me In leads to charge delocalization, ring expansion and formation of six-membered ring DMPyr [Me In(μ -S-InMe )] . The latter is a key intermediate in the formation of dianionic sulfidoindate DMPyr [(Me In) (μ -S) ] displaying an unusual inverse heteroadamantane cage structure with four capping sulfido ligands.