Attachment to manganese or cobalt of a bulky tri(organosilyl)methyl ligand containing an NMe2 or an OMe donor group

The organolithium compound LMe2)} reacted with one equivalent of MnCl2 to give [Me2)}]2 (4) and with 0.5 equivalent of MnCl2 to give Mn{C(SiMe3)2(SiMe2NMe2)}2 together with a small amount of the MnIII compound [Me2)}]2 (6) formed by adventitious admission of air. With CoBr2, the compound [Me2)}]2 (7) was obtained. The reaction between the lithium compound Me)} and MnCl2 in THF gave [Me)}]2 (5). The crystal structures of compounds 4, 5, 6 and 7 were determined. Compounds 4 and 5 are the first manganese analogues of Grignard reagents containing MnC σ-bonds to be characterised in the solid state.