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

The organolithium compound Li(THF)(2){C(SiMe3)(2)(SiMe2NMe2)} reacted with one equivalent of MnCl2 to give [Mn(mu-Cl){C(SiMe3)(2)(SiMe2NMe2)}](2) (4) and with 0.5 equivalent of MnCl2 to give Mn{C(SiMe3)(2)(SiMe2NMe2)}(2) together with a small amount of the Mn-III compound [Mn(mu-O){C(SiMe3)(2)(SiMe2NMe2)}](2) (6) formed by adventitious admission of air. With CoBr2, the compound [Co(mu-Br){C(SiMe3)(2)(SiMe2NMe2)}](2) (7) was obtained. The reaction between the lithium compound Li(THF)(2){C(SiMe3)(2)(SiMe2OMe)} and MnCl2 in THF gave [Mn(THF)(mu-Cl){C(SiMe3)(2)(SiMe2OMe)}](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 sigma-bonds to be characterised in the solid state. (C) 2002 Elsevier Science B.V. All rights reserved.