Structural study of amorphous tellurium(II) halides TeCl2-xIx (x = 0.5, 0.1): X-ray diffraction and reverse Monte Carlo simulations.

The addition of small amounts of iodine to thermodynamically instable TeCl2 yields amorphous, glassy tellurium(II) halides TeCl2-xIx (0.1 < x < 0.5), which were prepared by rapid quenching of melts with the respective compositions.

Polarization anisotropy of X-ray atomic factors and 'forbidden' resonant reflections.

Symmetry and physical aspects of 'forbidden' reflections excited by a local polarization anisotropy of the X-ray susceptibility are surveyed. Such reflections are observed near absorption edges where the anisotropy is caused by distortions of the atomic electronic states owing to interaction with neighbouring atoms. As a consequence, they allow for extracting nontrivial information about the resonant atom's local environment and their physical conditions.

Development of spin-labeled probes for adenosine receptors.

Functionalized xanthine derivatives bearing a nitroxide moiety at the 3- or 8-position were synthesized as electron paramagnetic resonance (EPR) probes. The 8-cyclopentyl-1-propylxanthine derivative 4, spin-labeled at N3 by substitution with a nitroxide-bearing dihydropyrrole moiety, was a potent and selective A(1) adenosine receptor antagonist (K(i) for A(1) 5.5 nM, 1600-fold selectivity vs A(2A), >200-fold vs A(2B), and 310-fold vs A(3) adenosine receptors).