title: Synthesis, structure, and physical properties for a series of trigonal bipyramidal M(II)-Cl complexes with intramolecular hydrogen bonds.
abstract: A series of transition metal chloro complexes with the tetradentate tripodal tris(2-amino-oxazoline)amine ligand (TAO) have been synthesized and characterized. X-Ray structural analyses of these compounds demonstrate the formation of the mononuclear complexes [M(II)(TAO)(Cl)](+), where M(II) = Cr, Mn, Fe, Co, Ni, Cu and Zn. These complexes exhibit distorted trigonal-bipyramidal geometry, coordinating the metal through an apical tertiary amine, three equatorial imino nitrogen atoms, and an axial chloride anion. All the complexes possess an intramolecular hydrogen-bonding (H-bonding) network within the cavity occupied by the metal-bound chloride ion. The metal-chloride bond distances are atypically long, which is attributed to the effects of the H-bonding network. Nuclear magnetic resonance (NMR) spectroscopy of the Zn complex suggests that the solid-state structures are representative of that observed in solution, and that the H-bonding interactions persist as well. Additionally, density functional theory (DFT) calculations were carried out to probe the electronic structures of the complexes.
authors.affiliation: Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025, USA.
authors.forename: Nathaniel S
authors.initials: NS
authors.lastname: Sickerman
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Park
authors.forename: Gary K-Y
authors.initials: GK
authors.lastname: Ng
authors.forename: Jefferson E
authors.initials: JE
authors.lastname: Bates
authors.forename: Mark
authors.initials: M
authors.lastname: Hilkert
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Ziller
authors.forename: Filipp
authors.initials: F
authors.lastname: Furche
authors.forename: A S
authors.initials: AS
authors.lastname: Borovik
mesh_terms: D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010080:Oxazoles / Q000138:chemical synthesis / Q000737:chemistry*; D028561:Transition Elements / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000588:Amines; D056831:Coordination Complexes; D010080:Oxazoles; D028561:Transition Elements; D002713:Chlorine