Amorphous Complexes MM (EDTA) (H2O)4 · 2H2O . LAXS and XPS Investigation of the Local Structure

Abstract The amorphous MM (EDTA)(H2O)4·2 H2O (M = Ni,Co) substances are made up of infinite chains of alternating "hydrated" and "chelated" octahedra bridged by carboxylate groups: M(H2O)4 - M(EDTA)-M(H2O)4-... . XPS enables to ascertain that the coordination of the EDTA ligand in the amorphous phase is identical to that in the crystalline phase, i.e., hexacoordination toward the M atom and two bridging groups in the Ni -Ni, Co - Co compounds.