Synthesis of Mn(III)X₃ (X = Cl, Br, I) Compounds with Phosphine (R₃P) Ligands

This work details the synthesis and characterization of complexes of the form [Mn^IIIX₃(PR₃)₂] (X = Cl, Br, I), which is a rare type of coordination compound. Prior to this work, the only mode of synthesis was oxidizing mixtures of Mn^IIX₂ and PR₃ with dry air, but these procedures give low yields and variable outcomes. By taking advantage of the starting material [Mn^IIICl₃(OPPh₃)₂] (<b>1</b>) and other new strategies, we present robust synthetic protocols for both new and known Mn(III) halido phosphine complexes. In addition to [Mn^IIIX₃(PR₃)₂], these include [Mn^IIICl₂(dmpe)₂]⁺ salts and [LMn^IIX₃]^- manganates (L = phosphine oxide). Furthermore, the full characterization of these [Mn^IIIX₃(PR₃)₂] species enabled a definitive revisitation of some controversial chemistry surrounding the compounds and products from the dry air oxidation of certain Mn^IIX₂ and phosphine ligand mixtures.