名称:
Synthesis and Characterization of Some New Manganese(II) Complexes, Manganese(III) Heterochelates, and µ‐Dioxo‐dimanganese(IV) Complexes Involving Tetradentate Schiff Bases
摘要:
Condensation of 1,3-diaminopropane-2-ol with diacetylmonoxime and acetylacetone yielded the tetradentate Schiff bases N,N'-(2-hydroxy) propylene-bis{(2-imino-3-oximino)butane} (H2L2) and N,N'-(2-hydroxy) propylene-bis(acetylacetoneimine) (H2L2), respectively. The ligands form mononuclear manganese(II) complexes of the type [Mn(II)(L-1)] (1) and [Mn(II)(L-2)] (3), which are used for the formation of the manganese(III) heterochelates of the type [Mn(III)(L)(L-L)] (where H2L = H2L1 or H2L2; L-L = anion of acetylacetone or salicylaldehyde). Cationic heterochelates of the type [Mn(L)(L-L)]ClO4 where H2L = H2L1 or H2L2 and L-L = ethylenediamine and N,N'-propylene-bis(benzaldimine) (L-3) have been synthesized by the reactions of bis(acetylacetonato)manganese(II) or bis(salicylaldehydato)manganese(H) with the preformed Schiff bases or by the reactions of [Mn(II)(L-1)] or [Mn(II)(L-2)] with L-L in absolute alcohol under reflux. Some of the complexes, synthesized here, may be used as precursors in the synthesis of higher nuclearity manganese complexes. Air oxidation of [Mn(II)(L-1)] (1) and [Mn(II)(L-2)] (3) in DMF yielded the dark-brown mu-dioxo-bis-[N,N'-(2-hydroxy)propylene-bis{(2-imino-3-oximino)butane}]dimangenese(IV) (2) and mu-dioxo-bis[N,N'-(2-hydroxy)propylenebis{(acetylacetoneimine)}]dimangenese(IV) (4) complexes, respectively. All of the complexes have been characterized with the help of elemental analyses, molar conductance values, molecular weights, magnetic moments, and spectroscopic (IR, UV-VIS, ESR) data.