STRUCTURAL CHARACTERIZATION OF HYBRID MATERIALS OBTAINED FROM ZIRCONIUM N-PROPOXIDE AND 1,2-ETHANEDIOL

Zirconium n-propoxide Zr(OPr(n))4 has been chemically modified by 1,2- ethanediol with molar ratio r = 0.5, 1 and 2. The properties of the hy brid organic-inorganic materials obtained after drying at 100-degrees- C for 24 h have been measured by thermal analysis, X-ray diffraction, infrared spectroscopy and C-13 NMR with cross-polarization at magic an gle spinning. Chemical modification of the zirconium precursor at a mo lecular level has been clearly detected, with a bridging coordination mode for 1,2-ethanediol. Application of a structure-dependent version of the partial charge model to the prediction of C-13 chemical shifts in modified zirconium alkoxides is also described.