X-ray crystal structures of carbonate and hydroxide bridged MnII/MgII heterobimetallic complexes formed by reduction of CO2 or H2O by a Mn0–MgII bonded compound

The previously reported Mn-0-Mg-II bonded heterobimetallic compound [L+Mn-Mg((Mes)Nacnac)] (L+ = -N(Ar+)(SiPr3i),Ar+ = C6H2{C(H)Ph-2}(2)Pri-2,6,4;(Mes)Nacnac = [((NCMe)-N-Mes)(2)CH](-); Mes = mesityl) forms an adduct complex, [L+Mn-Mg(THF)((Mes)Nacnac)], when dissolved in THF. Adventitious water is shown to be reduced by [L+Mn-Mg((Mes)Nacnac)] to give the hydroxide bridged heterobimetallic, [L+Mn(mu-OH)(2)Mg((Mes)Nacnac)]. The Mn-0-Mg-II bonded heterobimtallic reductively disproportionates CO2, affording the carbonate bridged species, [{L+Mn(mu-CO3)Mg(THF) ((Mes)Nacnac)}(2)], in the presence of THF. The three new compounds have been crystallographically characterized.