title: Triangular, ferromagnetically-coupled CuII 3-pyrazolato complexes as possible models of particulate methane monooxygenase (pMMO).
abstract: Magnetic susceptibility and EPR studies show that trinuclear Cu(II)-pyrazolato complexes with a Cu(3)(mu3-X)2 core (X = Cl, Br) are ferromagnetically coupled: J(Cu-Cu) = +28.6 cm(-1) (X = Cl), +3.1 cm(-1) (X = Br). The orderly transition from an antiferromagnetic to a ferromagnetic exchange among the Cu centers of Cu(3)(mu3-X) complexes, X = O, OH, Cl, Br, follows the change of the Cu-X-Cu angle from 120 degrees to approximately 80 degrees. The crystal structures of [Bu4N]2"[Cu3(mu3-Br)2(mu-pz*)3Br3] (pz* = pz (1a) or 4-O2N-pz (1b), pz = pyrazolato anion, C(3)H(3)N(2)(1-)) are presented.
authors.affiliation: Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico 00931-3346.
authors.forename: Roman
authors.initials: R
authors.lastname: Boca
authors.forename: L'ubomír
authors.initials: L
authors.lastname: Dlhán
authors.forename: Gellert
authors.initials: G
authors.lastname: Mezei
authors.forename: Tamara
authors.initials: T
authors.lastname: Ortiz-Pérez
authors.forename: Raphael G
authors.initials: RG
authors.lastname: Raptis
authors.forename: Joshua
authors.initials: J
authors.lastname: Telser
mesh_terms: D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D007501:Iron / Q000737:chemistry; D008280:Magnetics; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010105:Oxygenases / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
chemical_list: D009942:Organometallic Compounds; D003300:Copper; D007501:Iron; D010105:Oxygenases; C021555:methane monooxygenase