The physico-chemical properties of 2-methoxyphenoxyacetates of Mn(II), Co(II), Ni(II) and Cu(II)

Abstract

abstract:The complexes of 2-methoxyhenoxyacetates of Mn(II), Co(II), Ni(II) and Cu(II)with the general formula: M(C 9 H 9 O 4 ) 3 ·4H 2 O, where M(II) = Mn, Co, Ni and Cu have been synthesized and characterized by elemental analysis, IR spectroscopy, magnetic and thermogravimetric studies and also X-ray diffraction measurements. The complexes have colours typical for M(II) ions (Mn(II) -a pale pink, Co(II) -pink, Ni(II) -green, and Cu(II) -blue). The carboxylate group binds as monodentate and bidentate ligands. On heating to 1273K in air the complexes decompose in the same way. At first, they dehydrate in one step to anhydrous salts, that next decompose to the oxides of respective metals with the intermediate formation of the oxycarbonates. Their solubility in water at 293K is of the order of 10 -5 mol·dm -3 . The magnetic moments of analysed complexes were determined in the range of 76-303K. The results reveal them to be high-spin complexes of weak ligand fields.

XAFS studies of Cu(II) and Co(II) complexes with derivatives of cinnamic acid

“…The IR spectroscopy for the Cu(II) complex and for sodium salt of 4-nitrocinnamic acid and spectroscopic criteria [36,37] indicated that COOgroup coordinates monodently to the metal cation. XAFS studies confirmed the coordination via COOgroups and specified that the polyhedron of Cu(II) exhibits a square-planar geometry (CuO 4 ) with two carboxylate ligands coordinating in the monodentate mode and two aqua ligands (Fig.…”