New Organometallic and Coordination Chemistry Routes Towards Unsupported and Silica-Supported Bismuth-Based Oxide-Type Materials

Coordination and organometallic compounds containing bismuth, lanthanum or molybdenum are used as precursors for the preparation of unsupported or silica-supported Bi-based oxides. Bismuth (III) and lanthanum (III) polyaminocarboxylates, and more specifically homo- and heteropolymetallic complexes of triethylenetetraaminehexaacetic acid (H6ttha) are shown to constitute adequate precursors for the formation of mixed Bi2-xLaxO3 oxides at moderate temperatures. Silica-supported bismuth molybdates are obtained from impregnation or combined impregnation-deposition procedures involving Bi ß-diketonates, carboxylates or mixed acetate-Nmethylimidazole Bi complexes, in association with molybdenyl acetylacetonate or heteroleptic carbonyl-pyridine Mo complexes, either dissolved or dispersed in various organic solvents.