Abstract
Heating of the lithium magnesate [Li(THF)
2(μ-Br)
2Mg(Tsi)(THF)] (Tsi = (Me
3Si)
3C) under vacuum gives the dialkylmagnesium compound Mg(Tsi)
2, the first two-coordinate magnesium derivative to have been structurally characterized in the solid state. The compound is remarkably thermally stable, not decomposing (or melting) when heated to 350°C. It has a very low reactivity, failing to react in toluene with, for example, CO
2, Me
3SiCl, Me
2SiHCl, MeI, BCl
3 or CH
3COCl, and even with neat CH
3COCl at its boiling point. It does react, though fairly slowly, with I
2 in toluene to give TsiI, and more rapidly with Br
2 to give TsiBr, and with an excess of PhSO
2Cl in toluene at 1OO°C to give TsiCl. It decomposes quickly in the air, and reacts readily with MeOH in toluene to give TsiH without formation of detectable amounts of the intermediate TsiMgOMe, and with O
2 in toluene.