THE STRUCTURE AND CATALYTIC PROPERTIES OF COORDINATION POLYHEDRA OF 3D-METALS IN METAPHOSPHATE MELTS

By EAS and ESR spectroscopy, oxygenated complexes of d-metals have been established in high-temperature melts NaPO3-Cr2O3-O-2 and NaPO3-CoO-O-2 and others of the type M(PO3)(x)O-2, where M is Cr, Co, V, and their structure has been established. The O-18/O-16 exchange reaction in the NaPO3-V2O5-O-2 melt has been studied by mass spectrometry both in the presence of the oxidized substrate and in its absence. A general approach has been proposed explaining the interaction between polyphosphate complexes of 3 d-metal ions and molecular oxygen and the oxidation ability of the oxygenated complexes in terms of the MO theory. It has been established three types of interaction between 3 d-metal ions and molecular oxygen: donor, acceptor and donor-acceptor ones. Oxygenated complexes of the ions of the midle of the 3 d-element series (d(4)-d(7)) were found to possess the revealed ''partial'' oxidation ability towards alkanes.