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

A series of new organic ligands (5Z,5Z')-2,2'-(alkane-alpha,omega-diyldiselenyl)-bis-5-(2-pyridylmethylene)-3,5-dihydro-4H-imidazol-4-ones (L) consisting of two 5-(2-pyridylmethylene)-3,5-dihydro-4H-imidazol-4-one units linked with polymethylene chains of various lengths (n = 2-10, where n is the number of CH2 units) have been synthesized. The reactions of these ligands with CuCl2 center dot 2H(2)O and CuClO4 center dot 6H(2)O gave Cu2+ or Cu1+ containing mono- and binuclear complexes with Cu2LClx (x = 2-4) or CuL(ClO4)(y) (y = 1, 2) composition. It was shown that the agents reducing Cu2+ to Cu1+ in the course of complex formation can be both a ligand and an organic solvent in which the reaction is carried out. This fundamentally distinguishes the selenium-containing ligands L from their previously described sulfur analogs, which by themselves are not capable of reducing Cu2+ during complexation under the same conditions. A higher cytotoxicity and reasonable selectivity to cancer cell lines for synthesized complexes of selenium-containing ligands was shown; unlike sulfur analogs, ligands L themselves demonstrate a high cytotoxicity, comparable in some cases to the toxicity of copper-containing complexes.

Automated summary

A series of new organic ligands consisting of two 5-(2-pyridylmethylene)-3,5-dihydro-4H-imidazol-4-one units linked with polymethylene chains of various lengths have been synthesized. These ligands react with copper salts to form mono- and binuclear complexes containing Cu2+ or Cu1+, showing higher cytotoxicity and reasonable selectivity to cancer cell lines.