The first example of Cu(I) complex with 5-pyrazolyl-2-thioxotetrahydro-4H-imidazol-4-one: Synthesis and structural characterization

Abstract A new organic ligand 3-phenyl-5-((Z)-1,5-diphenyl-pyrazol-3-yl)methylene)-2-methylthio-4,5-dihydro-imidazol-4-one (L) has been synthesized by a two step reaction sequence starting from 3-phenyl-2-thiohydantoin and 3-formyl-pyrazoline. The complex of copper(I) with L2СuClO4 composition was obtained by the reactions of this ligand with Сu(ClO4)2·6H2O; thus, the reduction of copper(II) took place during the complex formation. The crystal structure of synthesized complex has been determined by X-ray analysis. Copper atom has a distorted tetrahedral ligand environment and coordinated by four nitrogen atoms of two ligand moieties; perchlorate ion does not participate in the coordination of the metal ion. This complex undergo reversible electrochemical reduction at − 0.32 V.