Reinvestigation of arylmanganese chemistry – Synthesis and molecular structures of [(thf)4Mg(μ-Cl)2Mn(Br)Mes], [Mes(thf)Mn(μ-Mes)]2, and (MnPh2)∞ (Ph = C6H5; Mes = mesityl, 2,4,6-Me3C6H2)

The reaction of 2,4,6-trimethylphenylmagnesium bromide (MesMgBr) with manganese(II) chloride in an equimolar ratio yields [(thf)4Mg(μ-Cl)2Mn(Br)Mes] (1) with two bridging chloro ligands and a Mn–C bond length of 2.136(5) Ǻ. A molar ratio of 2:1 leads to a metathesis reaction and the formation of [Mes(thf)Mn(μ-Mes)]2 (2) with two bridging mesityl groups. Whereas THF-free [MnMes2]3 crystallizes as a trimer from toluene solution, the reduced bulkiness of the phenyl groups in (MnPh2)∞ (3) leads to the formation of a chain-like structure with Mn–C bond lengths of 2.245(3) Ǻ.