4′-(Oxodiphenylphosphino)-2,2′:6′,2′′-terpyridine – crystal structure and complexes of cobalt(II) and cobalt(III)

The complex [Co(2)2]2+ (2 = 4′-(oxodiphenylphosphino)-2,2′:6′,2′′-terpyridine) has been prepared either by the direct reaction of 2 with Co(II) or by careful oxidation of [Co(1)2]2+(1 = 4′-(diphenylphosphino)-2,2′:6′,2′′-terpyridine). Further oxidation with H2O2 leads to [Co(2)2]3+. The 1H NMR spectra of the paramagnetic and diamagnetic [Co(2)2]2+ and [Co(2)2]3+ are reported. The crystal structure of ligand 1 has been determined; in the solid-state, 1 exhibits extensive intermolecular π–π stacking.