Synthesis, spectroscopic, photophysical and electrochemical behaviour of ruthenium(II) and copper(I) isocyano-bridged complexes with polypyridine ligands: 2,2′-bipyridine and 1,10-phenanthroline

New binuclear complexes with [Cu(PPh3)3]+ and [Cu(PPh3)(N—N)]+ (N—N – 2,2′-bipyridine, 1,10-phenanthroline) moieties connected via the isocyanide group to [Ru(bpy)2(py)]+ and [Ru(phen)2(py)]+ have been prepared and isolated as PF6− salts. In addition, new trinuclear complexes, [{(PPh3)3Cu(μ-NC)}2Ru(bpy)2](PF6)2 and [{(N—N)-(PPh3)Cu(μ-NC)}2Ru(bpy)2](PF6)2, have been synthesized using [Ru(bpy)2(CN)2]. The complexes have been characterized by elemental analyses, i.r., n.m.r., u.v.–vis., FAB mass spectra and by conductivity measurements. The i.r. spectra reveal an increase in v;(CN) in the isocyano-bridged complexes compared to the mononuclear parent complexes. The complexes are luminescent with emission wavelengths in the 458–550 and 600–636 nm ranges. The half wave reduction potentials in MeCN are always more positive than those of the parent complexes. It is observed that the isocyano-bridged complexes are more powerful excited state reductants than the cyano-bridged, Cu(I)(μ-CN)Ru(II) complexes.