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The X-ray magnetic circular dichronism (XMCD) study at the Gd M(sub 4,5-) and L(sub 2,3-) edges of two linear magnetic chains involving Gd(III) cations bridged by nitronyl nitroxide radicals is reported. The spectroscopy directly probes the magnetic moments of the 4f and 5d orbitals of the gadolinium ions.

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.

Research has been conducted on the pentanuclear octacyanotungstate(V)-based complex. The structure and magnetic properties of this complex have been investigated and the results are reported.

Research has been conducted on the low-spin iron(III) complexes used as ligands. The preparation and the crystal structure of the precursor complex PPh (sub)4[Fe (super)III (bipy)(CN) (sub)4].H (sub)2 O and its derivatives are described.

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.

Research has been conducted on the cyano-bridged copper(II) and nickel(II) homodinuclear complexes. The synthesis and structural characterization of these complexes have been carried out and described.

Research has been conducted on the relation between the structural and magnetic properties. The synthesis of the molecular materials which have both Cotton effects and ferromagnetic long range order has been carried out in investigating this relation and the results are presented.

The mononuclear PPh(sub 4)[Fe(phen(CN)(sub 4)].2H2O complex and the cyanide-bridged bimetallic compounds are synthesized and structurally characterized. A comparison between the magnetic properties of the isostructural compounds allows to check the antiferromagnetic coupling in M= Mn(II).

A single crystal of the title compound [Mn(super II)(sub 6)(H2O)(sub 9){W(super V)(CN)(sub 8)}(sub 4).13H2O](sub n) was synthesized in a hot aqueous solution containing octacyanotungstate, Na3[W(CN)(sub 8)].3H2O, and Mn(ClO)(sub 4))(sub 2).6H2O. It is concluded that modulating the reaction conditions resulted in obtaining a W(super V)(sub 4)-Mn(super II)(sub 6) polymeric compound as a single crystal.

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.

Research has been conducted on the synthesis of enantiomeric forms of two- and three-dimensional polymers. The structural characteristics of the polymers are presented.

A series of dimeric iron(II) spin-crossover [Fe(L)(NCS)2]2(bpym) compounds were synthesized by the reaction of [Fe(H2O)6] (ClO4)2 and KNCSe with a methanolic solution of bpym and methanol/dichloromethane. The dinuclear iron(II) spin-crossover compounds such as [Fe(bpym)(NCSe)2]2(bmpy) and [Fe(bt)(NCSe)2]2(bmpy) exhibited an average Fe-N bond distance of 0.2 angstrom for the high spin state. However, [Fe(bpym)(NCSe)2]2(bpym) has a shorter Fe-N bond distance compared to [Fe(bpym)(NCSe)2]2(bpym).

EXAFS and XANES spectra analyze the pressure and temperature induced solid state valence tautomeric transformations of (Co(II)(3,5-DTBSQ)2(phen))- (C6H5)CH. The cooling of toluene solvate between 270-215 K converts a high-spin Co(II) to a low-spin Co(III) complex. The tautomer has a bond length of 2.08 plus or minus 0.02 angstrom. The application of pressure causes the interconversion of low spin Co(III) to high spin Co(II) tautomer. The process of interconversion is reversible and occurs within the range of 0.075-2.5 GPa.

The pressure-induced iron(II) high-spin state (S = 2) to low-spin state (S = 0) crossover has been investigated in parent six-coordinate complexes of the type FeLnL'm(NCS)2, which exhibit thermally-induced spin transition under atmospheric pressure. The spin states were determined by near-edge X-ray absorption spectroscopy at room temperature. The low-spin fraction as a function of pressure was discussed in terms of the electronic, structural and thermodynamic characteristics of the complexes.

A dinuclear precursor (Cu2(bpm)2(H2O)2(OH)2(NO3)2).4H2O (bpm = 2,2-bipyrimidine) undergoes polymerization producing one-dimensional compounds exhibiting a regular alternation of ferro and antiferromagnetic couplings. X-ray studies of these compounds help understand the molecular structures. Magnetic susceptibility studies reveal the presence of significant intramolecular ferromagnetic coupling in a compound. In few compounds bpm bridge facilitates alternating anti ferromagnetic interactions, and hydroxo bridge participates in ferromagnetic interactions.

The copper complexes (Cu2(bpm)(NCO)4)n (bpm = bipyrimidine), (Cu(bpm)(NCS)2)n and (Cu2(bpm)(NCS)4)n were synthesized and their crystal structures, spectroscopic and magnetic properties were determined. The copper atoms in all the complexes were in a distorted octahedral surrounding. Infrared and electronic spectra were carried out to determine the coordination modes of bpm and the nature of the cyanate and thiocyanate bridging modes. The molar susceptibility data for the complexes were also presented.

The successful synthesis of two oxamidato complexes from the reaction of Cu(II) and Ni(II) ions with oxamide-N,N'-diacetic acid (H4glyox) shows the ability of N,N'-disubstituted oxamides to form mono-, di- and polynuclear complexes. The crystallographic and structural analyses of the derived complexes, (Cu H2glyox H2O 3 .4H2O)n and (Ni2 glyox H2O 6).4H2O, reveal that the oxamidato ligand functions as a bis-tridentate in the Cu-complex but in the Ni-complex, it functions as a bis-monodentate. The complexes exhibit magnetic properties both in the solution and solid-state forms.