Copper and palladium complexes with substituted pyrimidine-2-thiones and 2-thiouracils: syntheses, spectral characterization, and X-ray crystallographic study

All complexes were characterized by elemental analysis, IR, 1 H, and 13 C NMR spectroscopy. To assign bands in the IR spectra of L 1 and L 2 and complexes with Cu(I) and Pd(II), deuterium substitution of movable protons at N-atoms was used.

The crystal structures of two compounds, [Cu(L 2 ) 2 Cl] and [Pd(L 4 ) 2 Cl 2 ], were determined by X-ray single-crystal and powder diffraction, respectively. In [Cu(L 2 ) 2 Cl], copper has a rare coordination number of three and triangular surrounding of two neutral L 2 molecules, coordinated through sulfurs, and chloride. In [Pd(L 4 ) 2 Cl 2 ], palladium has a standard square-planar geometry, formed by two uracil molecules and two chlorides.