For Keggin-type polyoxometalate complexes (α-[XMo12O40]n− (X = S, P, As, Si, Ge; n = 2–4) and α-[XW12O40]n− (X = S, P, As, Si, Ge, B, Al; n = 2–5)), the conversion processes of the first two one-electron waves into a two-electron wave were investigated in dipolar aprotic solvents containing H+, Li+, or Na+ as a Lewis acid. A simulation of the cyclic voltammogram indicated that the potential difference (ΔEmid) between the first one- and two-electron redox waves served as a useful criterion for the basicity of the Keggin anions. According to the ΔEmid values, the Keggin anions were classified into the following four groups: (1) [SW12O40]2−; (2) [SMo12O40]2−, [XW12O40]3− (X = P, As); (3) [XMo12O40]3− (X = P, As), [XW12O40]4− (X = Si, Ge); (4) [XMo12O40]4− (X = Si, Ge), [XW12O40]5− (X = B, Al). The voltammetric properties of the Keggin anions were systematized with reference to their basicities.

A complete series of copper(ii) halide complexes [CuX(tptm)](X = F (), Cl (), Br (), I (); tptm = tris(2-pyridylthio)methyl) with a novel Cu(II)-C(sp(3)) bond has been prepared by the reactions of [Cu(tptm)(CH(3)CN)]PF(6)(.PF(6)) with corresponding halide sources of KF or n-Bu(4)NX (X = Cl, Br, I), and the trigonal bipyramidal structures have been confirmed by X-ray crystallography and/or EPR spectroscopy. The iodide complex easily liberates the iodide anion in acetonitrile forming the acetonitrile complex as a result. The EPR spectra of the complexes showed several superhyperfine structures that strongly indicated the presence of spin density on the halide ligands through the Cu-X bond. The results of DFT calculations essentially matched with the X-ray crystallographic and the EPR spectroscopic results. Cyclic voltammetry revealed a quasi-reversible reduction wave for Cu(II)/Cu(I) indicating a trigonal pyramidal coordination for Cu(I) states. A coincidence of the redox potential for all [CuX(tptm)](0/+) processes indicates that the main oxidation site in each complex is the tptm ligand.

The spectroscopic properties of dye monolayers on silver films were determined by using the technique of attenuated total reflection (ATR). The dyes N,N′-di(methyloctadecyl) squarylium and N,N′-dioctadecyloxacarbocyanine were deposited on silver films by the Langmuir–Blodgett monolayer technique. From a least squares fit of the experimental ATR curves to the exact reflection formula, the dielectric function of the dye monolayers was determined in the visible wavelength region. It was found that squarylium forms ordered layers with a regular array of molecules and a film thickness equal to the length of the molecule (2.66 nm). These films were characterized by a strong absorption band at λs=530 nm (dimer band) and were highly anisotropic, the transition dipole moment lying in the plane of the monolayer film. Undiluted cyanine dye films on silver, on the other hand, showed a thickness less than that expected from the length of the molecule and a high degree of disorder. Increasing regularity in arrangement and growing thickness were observed when the cyanine dye was diluted with cadmium arachidate. For both the pure and diluted cyanine dye monolayers, two absorption bands have been measured in the visible region (a monomer band at λs=500 nm and a dimer band at λs=464 nm) and it was confirmed that their relative intensities depended on the mixing ratio of cyanine dye to Cd–arachidate.

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