Copper‑, Palladium‑, and Platinum-Containing Complexes of an Asymmetric Dinucleating Ligand

The coordination chemistry of an asymmetric dinucleating hexadentate ligand LH2 comprising neutral alkyltriamine and potentially dianionic dicarboxamido-pyridyl donor sets with copper, palladium, and platinum has been explored. Monometallic, dicopper, and heterodinuclear Cu–Pd and −Pt complexes have been prepared and characterized, including by NMR, EPR, UV–vis, and IR spectroscopy and X-ray crystallography. For example, the monometallic complexes [(LH2)­MCl]­X (M = Cu, X = OTf; M = Pd or Pt, X = Cl) were prepared, wherein the metal­(II) ions are coordinated to the triamine portion and the pyridyldicarboxamide is unperturbed. Treatment of LH2 with [MesCu]x (Mes = mesityl) provided a monocopper­(I) complex, again with the metal coordinated only to the trialkylamine donor set. Reaction of [(LH2)­CuCl]­OTf with NaOMe resulted in an unexpected migration of the copper­(II)–chloride fragment to the pyridyldicarboxamide site to yield Na­[LCuCl], from which a dicopper complex LCu2Cl2 and mixed-metal complexes LCu­(Cl)­M­(Cl) (M = Pd, Pt) were prepared by addition of CuCl2 or MCl2, respectively. The heterodinuclear complexes were also prepared by addition of CuCl2 to [(LH2)­MCl]­Cl.