[Cu(en)2]2+ - [W(CN)6(bpy)]2- interactions in cyanido bridged and not linked complexes – structural study

•Five heterobimetallic Cu(II)-W(IV) complexes were synthesized and described.•The effect of a halogen or alkali metal addition to the structures was discussed.•X-Ray crystal structure analysis confirms cyanido bridiging in all structures.•The reflectance and IR spectra analysis was presented. Five heterobimetallic Cu(II)-W(IV) complexes with the general formulas [Cu(en)2][W(CN)6(bpy)], {[Cu(en)2][W(CN)6(bpy)]}2∙[Cu(en)2(H2O)2]X2 (where X = Cl or Br), Na4K2[Cu(en)2][W(CN)6(bpy)]4, Li2[Cu(en)2(H2O)2][W(CN)6(bpy)]2 were synthesized and described by elemental analyses, magnetic measurements, IR and UV–Vis spectra, as well as the single crystal X-ray structure measurements. In structures, the copper atoms adopt the geometry of a slightly distorted octahedron. The effect of the addition of a halogen or alkali metal on the different modes of cyanide bridging in all structures was discussed. These results provide an important contribution to the knowledge on the controllable synthesis of coordination networks based on cyanide bridges. [Display omitted]