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The enantioselective catalysis of 1,3-dipolar cycloaddition reaction of nitrones with propioloylpyrazole and acryloylpyrazole derivatives in presence of a chiral copper(II) complex of 3-(2-naphthyl)-L-alanine amide is described. The reaction is the first successful method for the catalytic enantioselective 1,3-dipolar cycloaddition of nitrones with acetylene derivatives.

Two highly porous coordination polymers, containing rare octanuclear hydroxo-nickel clusters and long bis-pyrazolyl spacers are reported. The polymers are found to possess lattice cavities up to 72% of the total crystal volume after mild thermal treatment.

A novel iridium(III) complex is described, where the complex has shown as intramolecular face-to-face [pi]-stacking between the phenyl ring of the dmppz ligand and the pendant phenyl of the pbpy ligand. The high stability is favored by the presence of pendant methyl groups on the dmppz ligands that has hindered the entrance of water molecules rendering the degradation of the complex more difficult.

Detailed photophysical studies was performed on a series of Cu(I)-responsive fluorescent probes that are based on a 16-membered thiazacrown receptor ([16]aneNS3) tethered to 1,3,5-triarylpyrazoline-fluorophores to determine the possible involvement of Cu(I) in adverse quenching pathways. The combined photophysical, electrochemical, and solution chemistry experiments demonstrated that electron transfer from Cu(I) does not compete with radiative deactivation of the excited fluorophore, indicated that Cu(I)-induced fluorescence switching is kinetically controlled.

[Co[(N[O.sub.3]).sub.2]L] (L: 2,6-di(pyrazol-1-yl)pyrazine) has displayed an abrupt transition with hysteresis in magnetic susceptibility. The results of spectroscopic and XRD measurements have shown that the complex is in the high spin state and the hysteresis is not due to a spin transition but has corresponded to a partial quenching of the angular momentum contribution to the magnetic susceptibility.

The formation of a flexible, microporous metal-organic framework Co(1,4-benzenedipyrazolate), with good thermal stability and high internal surface area is discussed. The framework is shown to easily adsorb [H.sub.2] with hysteresis, which is completely dependent on the temperature.

The synthesis and characterization of the platinum dimer and heteropolynuclear platinum complexes of 3,5-dimethylpyrazolate ([[Pt.sub.2][M.sub.4][([Me.sub.8]pz).sub.8]] (M = H, Ag, Cu)) are described. The yellow, sky-blue and orange luminescences of these complexes have shown that the emission energy can be controlled by the change of incorporated cations.

An efficient and modular approach for the regiocontrolled preparation of pyrazoles having substituents of all three-carbon atoms is described. The method uses an easily switchable metal-directing group to enable sequential direct lithiation of the 3- and 5-positions of the pyrazole ring.

Ruthenium and osmium complexes of the general formula M[Cl.sub.2][(PyP).sub.2] (PyP = P,N- donor ligand 1-(2-diphenylphosphinoethyl)pyrazole) are prepared from M[Cl.sub.2][(P[Ph.sub.3]).sub.3] (M = Ru or Os). The isomerization process has involved dissociation and rebinding of the [Cl.sup.-] coligand, with the possibility of Ru-N bond dissociation also occurring.

Binucleating ligands 3,5-bis{bis[(N-R-ureaylato)-N-ethyl]-aminomethyl}-1H-pyrazolate were used for the preparation of new [Co.sup.II]-[mu]-OH-[Co.sup.II] dimers. Findings reveal that the orientation of the acetate ligand within the H-bonding cavity was dependent on the size of the R substituent appended from the urea groups.