title: Crystal structures and magnetic properties of nickel complexes with hydrotris(pyrazolyl)borate ligand and double bridged by phosphate esters.
abstract: The reaction between [NiTp*(μ-OH)]2 (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) and (RO)2P(O)OH (R = Et, Bu, 4-NO2-Ph) affords the dinuclear nickel phosphates [NiTp*(μ-O2P(OR)2)]2 (R = Et (1), Bu (2), 4-NO2-Ph (3)), which have been studied by spectroscopic methods (IR, UV-vis, and (1)H NMR). In chloroform solution, those complexes exhibit isotropically shifted (1)H NMR resonances. Their molecular structures reveal that they all have an eight-membered Ni2O4P2 ring which possesses two nickel centers bridged to each other by two isobidentate phosphate ligands. Magnetic studies on 1-3 and other similar complexes (4 and 5) reveal antiferromagnetic behavior at low temperatures as well as an interesting correlation between calculated D values and the planarity of eight-membered Ni2O4P2 rings.
authors.affiliation: Departamento de Química Inorgánica, Universidad de Murcia, E-30071 Murcia, Spain.
authors.forename: Luisa
authors.initials: L
authors.lastname: López-Banet
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Santana
authors.forename: Gabriel
authors.initials: G
authors.lastname: García
authors.forename: Luis
authors.initials: L
authors.lastname: García
authors.forename: José
authors.initials: J
authors.lastname: Pérez
authors.forename: Teófilo
authors.initials: T
authors.lastname: Rojo
authors.forename: Luis
authors.initials: L
authors.lastname: Lezama
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Costes
mesh_terms: D000465:Algorithms; D001881:Borates / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D007202:Indicators and Reagents; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D001881:Borates; D004952:Esters; D007202:Indicators and Reagents; D008024:Ligands; D010710:Phosphates; D011720:Pyrazoles; C515919:hydrotris(pyrazolyl)borate; D009532:Nickel