Synthesis and characterization of manganese(ii) complexes supported by cyclopentadienyl-phosphine ligands

Abstract

A series of manganese(II) complexes supported by cyclopentadienyl-phosphine ligands have been synthesized and characterized. A reaction of potassium salts of a cyclopentadienyl-phosphine ligand (LK) with MnX₂ provided dimeric complexes [LMn(μ-X)]₂ (X = Cl, 1a; X = Br, 1b) in high yields. The monomeric complex [K(18-crown-6)][LMnCl₂] (2) was obtained with the addition of 18-crown-6. [LMn(μ-Cl)]₂ (1a) served as a precursor to dimeric amido and methyl manganese(II) complexes including [LMn(μ-NH₂)]₂ (3) and [LMn(μ-Me)]₂ (4). Treatment of [LMn(μ-Cl)]₂ (1a) with EtMgCl, PhMgBr or other reductants resulted in the formation of sandwich manganese(II) complex L₂Mn (5). Complexes 1a,b, 2–5 were characterized by a single-crystal X-ray structural analysis.