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The syntesis and the caracterization of some bis-cyclopentadienyl hafnium derivatives were realized. Hafnium (IV) compounds were identified by NMR spectroscopy, thermogravimetric measurements and mass spectrometry methods. The temperature dependencies of saturated vapor pressure were obtained using Knudsen method. Thermodynamic parameters of sublimation processeswere calculated. Thermal decomposition processes in vacuum and in an oxigen atmosphere were studied by high temperature mass spectrometry and gas by-products were determined, The volatile Cp2Hf(NEt2)2 and Cp2HfMe2 precursors were used for the Hafnium oxide films deposition using the MOCVD tecnique. The films were characterized by X-ray diffraction and IR-spectroscopy methods. X-ray diffraction patterns show the formation of monoclinic HfO2 phase.

Mononuclear copper(II) and nickel(II) complexes [M(H2LA)] have been obtained by reaction of the appropriate metal acetate with the potentially hexadentate compartmental ligand H4LA, prepared by condensation of 2,3-dihydroxybenzaldehyde with ethylenediamine. Physicochemical data suggest the metal ion is in the inner N2O2 compartment. An X-ray investigation on [Cu(H2LA)] showed that the crystals are orthorhombic, space group Pnca, with a= 19.381(5), b= 15.327(4), c= 10.158(4)Å for Z= 8 and confirms the inner occupancy of copper(II) which exhibits an almost square-planar configuration. The bond lengths to CuII[Cu-N 1.93(1), Cu-O 1.89(1)Å(mean)] are within the usual range. The complexes [M(H2LA)] act as ligands in the formation of heterodinuclear [M1M2LA(X)(solv)n](M1= Cu or Ni, M2= La or Y, X = NO3 or Cl) or [M1M2LA(solv)n](M = Cu or Ni, M2= UO2 or Ba) species [solv = H2O, methanol or dimethyl sulphoxide (dmso)]. Crystals of [{CuY(LA)(NO3)(dmso)}2]·2dmso, grown from dmso-MeOH are triclinic, space group P[1 with combining macron], with a= 9.919(5), b= 11.357(5), c= 13.789(6)Å for Z= 1 (the asymmetric unit is half of the molecule). The X-ray structure shows that the copper(II) is four-co-ordinated in the inner N2O2 compartment while the yttrium(III) is eight-co-ordinated in the outer O2O2. The complex is a tetranuclear asymmetric unit, two yttrium(III) ions being held together by phenolic oxygen bridges. The Y-O(ligand) bonds are in the range 2.28-2.40 Å, Y-O(dmso) is 2.31(1)Å and Y-O(nitrate) are 2.48 Å(mean). The Cu Y and Y Y distances are 3.397(3) and 3.781(2)Å respectively. The co-ordination of each yttrium(III) ion is completed by the oxygens of a bidentate nitrate ion and a dmso molecule. The geometry around the metal ion can be described as pentagonal bipyramidal. Two dmso molecules are present in the cell as clathrate solvent. The thermal decomposition of copper(II)-yttrium(III) and -lanthanum(III) complexes and the consequent formation of mixed oxides have also been studied and the preliminary results are reported.

Macrocyclic and macroacyclic polynucleating compartmental ligands have been prepared by condensation of 2,6-diformyl-4-chlorophenol and 1,8-diamino-3,6-dioxaoctane or 2,3-dihydroxybenzaldehyde with the ethylenediamine. These ligands, produce, by reaction under suitable conditions, homo and heterodinuclear complexes, containing d and/or f metal ions and/or barium which have been characterized also by x-ray diffractometry. These complexes have been used as useful precursors in the formation of crystallographically pure mixed oxides by their thermal decomposition. The composition and the properties of these oxides have been studied by x-ray powder diffraction, electron microscopy and x-ray fluorescence techniques together with magnetic and optical investigations.