Synthesis and characterization of diimine–diselenolene complexes of nickel and platinum: examining the influence of the chalcogenide atom

[(bpy)Pt(bds)], 1, (bpy-2,2′-bipyridine,bds-1,2-benenediselenolene) was prepared in good yield by the reaction of [(bpy)PtCl2] with bdsNa2, which was generated in situ by reduction of oligomeric [bds]n. The analogous nickel complex [(bpy)Ni(bds)] (2), was generated in a similar fashion but could not be isolated cleanly. UV–Vis and electrochemical examination of these complexes show that the substitution of selenium atoms for sulfur atoms found in the related dithiolene complexes [(bpy)Pt(bdt)] (3), and [(bpy)Ni(bdt)] (4) (bdt=1,2-benzenedithiolene) results in a small, but significant, alteration of the optical and electronic properties of this class of complexes. 1 was structurally characterized as both its CH2Cl2 solvate (P21/n – a=8.5298(10) Å, b=11.3461(2), c=19.1864(2), β=99.309(10)°, V=1832.40(4) Å3, Z=4) and its DMSO solvate (P21/c – a=11.1725(10) Å, b=20.7304(10) Å, c=8.3882(10) Å, β=99.926(10)°, V=1913.71(3) Å3, Z=4). With the exception of the incorporation of lattice solvent, both structures of 1 are essentially identical to that observed for 3 and 4 at both the molecular and supramolecular level.