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A study is conducted to clarify the nature of the zinc phase present in Zn/SiO2 samples not only after calcination, but also after drying. It is found that after drying at 25 or 50 degree C, the supported zinc phase is an amorphous nitrate, whereas after drying at 200 degree C, it is almost already fully transformed into zinc silicate.

A new synthetic procedure to obtain vanadium-chromium Prussian blue analogues is presented, using controlled amount of V(super III) in solution during the synthesis. The presence of weak amounts of V(super III) during the synthesis provides materials, which are better-organized and present reproducible Curie temperature and magnetization at saturation in agreement with the observed V/Cr stoichiometry.

Studies of the synthesis of a series of CoFe Prussian blue analogues which were tuned the amount of Cesium cations inserted in the tetrahedral sites of the structure. Structure and electronic structure have been investigated, combining XANES, infrared spectroscopy, powder X-ray diffraction experiments and magnetization measurement and the change of magnetization induced by light along the series shows that the efficiency of the photoinduced magnetization depends on a compromise between the number of excitable diamagnetic pairs and the amount of [Fe(CN)(Sub 6)] vacancies giving the network flexibility.

An analysis of the structure of a synthesized Prussian blue analogue using x-ray absorption spectroscopy is discussed. The results which increase our knowledge of the photoinduced electron transfer are presented.

Prussian blue compounds were synthesized to study the effect of photoinduced magnetization. The resulting structures with varying amounts of cobalt were examined and are presented.

The role of silica during impregnation by ammonia solutions of different Ni(II) concentrations at different hydrogen ion concentrations with or without washing operations in investigated. Results indicate the importance of the preliminary preparation steps of Ni/SiO2 materials. The support may either operate as dispersing agent, a macroanion or a chemical reagent depending on the pH. Moreover, the drying step results in the removal of ammine ligands, leading to silicate formation.

The electronic and local structure of the photoinduced metastable magnetic state of the Prussian blue analogue were characterized. In order to determine directly the relative orientation of the magnetic moments of Co(Super II) and Fe(Super III) ions in the metastable state, and the nature of the exchange interaction between them X-ray magnetic circular dichroism (XMCD) experiments at cobalt and Iron K edges.

A new trinuclear oxalamide cobalt triple mesocate with two redox states and dramatically different magnetic properties are used to demonstrate redox-based, ferromagnetic 'metal-organic switches'. The two terminal high-spin [d.sup.7] [Co.sup.II] ions (S = 3/2) that are ferromagnetically coupled in the homovalent tricobalt(II) reduced state are found to become uncoupled in the heterovalent tricobalt(II,III,II) oxidized state ([2.sup.ox]) upon one-electron oxidation of the central low-spin [d.sup.7] [Co.sup.II] ion (S = 1/2) to a low-spin [d.sup.6] [Co.sup.III] ion (S = 0).

The syntheses of templated assembly of [[Ru.sup.II][(bpy).sub.3]]- [[Pd.sup.II.sub.2][(ox).sub.3]], Pd2 and [[Ru.sup.II][(bpy).sub.3]][[Pd.sup.II][Mn.sup.II][(ox).sub.3]], PdMn are described. X-ray absorption spectroscopy results revel an unusual 6-fold oxygen environment around the Pd(II) atoms and due to this palladium(II) has a triplet (S=1) ground state.

The photomagnetic cyanide-bridged Cu-Mu bimetallic assembly, Cu(sub 2)(super II)[Mo(super IV)(CN)(sub 8)].8H2O (Cu(super II), S = 1/2; Mo(super IV), S = 0), which has an intervalence transfer (IT) band from Mo(super IV)-CN-Cu(super II) to Mo(super IV)-CN-Cu(super I) around 480 nm, is studied. The analysis has shown that the magnetic properties of a molecule-based material are reversibly switched between paramagnetic and ferromagnetic states by irradiating Cu(sub 2)(super II)[Mo(super IV)(CN)(sub 8)].8H2O solid with visible lights.

The synthesis and characterization of the first carbene derivative of polyoxometalate, [(PW9O34)(Sub 2)(cis-WO2)(cis-RuL(Sub 2)(Super Me)], (super -13) which displays an original molecular structure is presented. The study shows that the position of the rising edge is dependent on the oxidation state of ruthenium, and the higher the oxidation state, the higher its energy.

Cyclodextrins (CD) molecules have two hydrophilic hydroxyl faces that surround a hydrophobic cavity, one face makes the molecules suitable for preparing self-organizing systems. An eight-carbon chain is essential for constituting stable layer during the formation of Langmuir layers by amphiphilic molecules. Langmuir compression isotherms also show formation of molecular monolayers at the air-water interface by 6-bromo-6-deoxy-cyclodextrins.

The crystal structure of the first beta-cyclodextrin-pyridine-water compound was investigated. The structure of the compound consists of packings of beta-cyclodextrin (beta-CD) monomers. Inter- and intramolecular channels possess eight pyridine molecules per beta-CD, with three water molecules ouside the cavity. A pyridine is in the beta-CD cavity and another is at the primary hydroxy level. The rest occupy thetwo channels oriented along the crystallographic 2-fold screw axis.

The substitution of chromium in lithium manganate spinels having a composition of LiCrxMn2-xO4 has been studied in relation to the lithium extraction and insertion reactions. X-ray absorption near-edge structure spectroscopy is used in investigating the local structural environments and electronic states of chromium and manganese. It has been observed that substituted Cr forms Cr3+ ions at the Mn site and the Cr ions remain in the trivalent state during lithium extraction and insertion.

Examines the photoinduced ferrimagnetic systems in a CoFe Prussian blue analogue. Correlation between the photoinduced electron transfer and a local structural rearrangement of the coordination sphere; Generation of magnetic domains through the molecular excitation of diamagnetic pairs; Elongation of the bond during electron transfer.