Copper coordination compounds with (5,5')-2,2'-(alkane-α,ω-diyldiselenyl)-bis-5-(2-pyridylmethylene)-3,5-dihydro-4-imidazol-4-ones. Comparison with sulfur analogue.

A series of new organic ligands (5,5')-2,2'-(alkane-α,ω-diyldiselenyl)-bis-5-(2-pyridylmethylene)-3,5-dihydro-4-imidazol-4-ones (L) consisting of two 5-(2-pyridylmethylene)-3,5-dihydro-4-imidazol-4-one units linked with polymethylene chains of various lengths ( = 2-10, where is the number of CH units) have been synthesized. The reactions of these ligands with CuCl·2HO and CuClO·6HO gave Cu or Cu containing mono- and binuclear complexes with CuLCl ( = 2-4) or CuL(ClO) ( = 1, 2) composition. It was shown that the agents reducing Cu to Cu in the course of complex formation can be both a ligand and an organic solvent in which the reaction is carried out.

Novel Copper-Containing Cytotoxic Agents Based on 2-Thioxoimidazolones.

A series of 73 ligands and 73 of their Cu and Cu copper complexes with different geometries, oxidation states of the metal, and redox activities were synthesized and characterized. The aim of the study was to establish the structure-activity relationship within a series of analogues with different substituents at the N(3) position, which govern the redox potentials of the Cu/Cu redox couples, ROS generation ability, and intracellular accumulation. Possible cytotoxicity mechanisms, such as DNA damage, DNA intercalation, telomerase inhibition, and apoptosis induction, have been investigated.

Rotational and translational diffusion of spin probes in room-temperature ionic liquids.

We have studied the rotational and translational diffusion of the spin probe 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL) in five imidazolium-based room-temperature ionic liquids (RTILs) and glycerol by means of X-band electron paramagnetic resonance (EPR) spectroscopy. Rotational correlation times and rate constants of intermolecular spin exchange have been determined by analysis of the EPR line shape at various temperatures and spin probe concentrations. The model of isotropic rotational diffusion cannot account for all spectral features of TEMPOL in all RTILs.