Syntheses, molecular structures, and spectroscopic properties of manganese(II)/(III) complexes with tetraphenylimidodiphosphinato and bi-pyridine or salicylaldehyde ligands

Abstract

Treatment of [Mn(CH3COO)2·4H2O] with two equivalents of K[N(Ph2PO)2] in the presence of one equivalent of 2,2′-bipyridine (bpy) or 5,5′-dimethyl-2,2′-bipyridine(dmbpy) in ethanol resulted in the formation of the mono-nuclear manganese(II) complexes [Mn{η1ON(Ph2PO)2}{N(Ph2PO)2}(EtOH)(bpy)] (1) and [Mn{N(Ph2PO)2}2(dmbpy)] (2), respectively. Interaction of [Mn(CH3COO)2·4H2O], K[N(Ph2PO)2] and salicylaldehyde or 5-chlorosalicylaldehyde or 3,5-dibromosalicylaldehyde in the presence of triethylamine in methanol gave the bi-nuclear manganese(II) complexes [Mn2{N(Ph2PO)2}2(μ,η2-O,O′-Sal)2(MeOH)2] (3) and [Mn2{N(Ph2PO)2}2(μ,η2-O,O′-5-Cl-Sal)2(MeOH)2] (4), and a tetra-nuclear manganese(II)/(III) complex [Mn4{N(Ph2PO)2}2(μ,η2-O,O′-3,5-Br2-Sal′)2(MeOH)4(μ-OMe)2(μ3-OMe)2] (5), respectively. All complexes were characterized by infrared and ultraviolet spectroscopy, their molecular structures were unambiguously established by single crystal X-ray diffraction. The electrochemical properties of complexes 1–5 were also investigated in the paper.