THERMAL-BEHAVIOR OF COPPER-DIMETHYL-PHENANTHROLINE SPECIES IN ALPHA-ZIRCONIUM AND GAMMA-ZIRCONIUM PHOSPHATES

Two methods are described in order to obtain copper-2,9-dimethyl-1,10-phenanthroline (dmp) coordination compounds intercalated between the layers of alpha-Zr(HPO4)2.H2O and gamma-(Zr(H2PO4)(PO4).2H2O: the direct intercalation of Cu-dmp complex species or the formation 'insitu' of coordination compounds. With the first exchanger both methods lead to similar products with X-ray diffraction patterns practically identical. They contain Cu(II-I)-dmp complex species that confer to the solids an initially green colour slowly turning to yellow with time or temperature when the reduction of Cu(II) to Cu(I) is complete. With gamma-ZrP(H2PO4)(PO4).2H2O, only the direct insertion is successful. TG/DTA experiments permit a better understanding of what is occurring in the materials during the copper reduction step, in correspondance of which, a strong endothermic peak and a gain in weight can be observed, They also show how the difference in the structure and chemical formula of the two exchangers affect the thermal behaviour of the two series of compounds.