Spectral and thermal properties of hydrazinium metal(II) ethylenediaminetetra¬acetates: Crystal structure of a novel seven coordinated manganese(II) complex

Abstract

Some new hydrazinium metal(II) ethylenediaminetetraacetates, (N₂H₅)₂[M(EDTA)] where M = Co, Ni, Cu or Zn and (N₂H₅)₃[M(EDTA)(H₂O)](NO₃)(H₂O) have been prepared and characterized by analytical, spectral and thermal techniques. The conductivity and infrared spectral data acquired for these complexes suggest the ionic nature of hydrazinium cations. Magnetic moments and electronic spectra indicate the octahedral geometry around the metal ions with EDTA serving as a hexadentate ligand. The crystal structure of hydrazinium aquoethylenediaminetetraacetatomanganate nitrate monohydrate has been determined from single crystal X–ray analysis. The crystallographic data for this compound are: orthombic, space group P2₁/c with a = 8.934(5), b = 12.712 (5), c = 19.514 (5) Å with Z = 4 and R = 0.0248. The manganese ion is seven coordinated with four carboxylate oxygen atoms and two nitrogen atoms from EDTA occupying six coordination sites while the seventh site is occupied by a water molecule. These complexes undergo multi–step degradation to give the respective metal oxides as the residue.