The Study of the Mechanism of the Local Order Formation near the Iron Atoms during Thermolysis of [Fe3O(OOCCH=CHCOOH)6]OH · 3H2O as the Initial Stage of Nanoparticle Nucleation in Metal–Polymer Systems1

Rearrangement of local order near the Fe atoms was analyzed by the EXAFS spectroscopy during thermal transformation of polymerizing Fe₃O(OOCCH=CHCOOH)₆]OH · 3H₂O. The following processes were disclosed to be involved in the thermolysis: dehydration with simultaneous rearrangement of the ligand environment, partial removal of maleic acid molecules, and thermal polymerization of the rearranged monomer with the conserved coordination of a trinuclear Fe₃O fragment with maleic ligands. The metal carboxylate Fe₃OR₆] cluster decomposes without the metal–metal bonding at the initial stage of decarboxylation followed by the formation of Fe–O-containing phases. This process can be considered as the nucleation of nanoparticles in the metal–polymer system.