title: Magnetic and structural properties of dinuclear singly bridged-phenoxido metal(II) complexes.
abstract: The reaction of a methanolic solution containing the bi-compartmental phenolic ligand 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-chlorophenol (L(Cl)-OH) with MCl2·nH2O in the presence of NH4PF6 or NaClO4 afforded the dinuclear bridged-phenoxido dichlorido-metal(ii) complexes [Co2(μ-L(Cl)O)(H2O)2Cl2][Co2(μ-L(Cl)O)(MeOH)2Cl2](PF6)2 (), [Ni2(μ-L(Cl)O)(MeOH)2Cl2]PF6 (), [Ni2(μ-L(Cl)O)(MeOH)(H2O)Cl2]ClO4·1.25H2O (), [Cu2(μ-L(Cl)O)Cl2]PF6·1/2MeOH () and [Zn2(μ-L(Cl)O)Cl2]PF6·MeOH (). The complexes were characterized by elemental microanalyses, conductivity measurements, IR and UV-Vis spectroscopy, mass spectrometry and single crystal X-ray crystallography. Each M(ii) center within the dinuclear complex cations is octahedrally coordinated in complexes , and five-coordinated distorted square pyramidal in and . Magnetic susceptibility measurements at variable temperature of the complexes revealed weak to moderate antiferromagnetic coupling with |J| values = 8.38, 39.0, 30.2 and 0.79 cm(-1), respectively. The results of DFT calculations correlate well with the experimentally determined antiferromagnetic coupling and show that the magnetic exchange coupling occurs mainly through the phenoxido bridge M-O-M. Implications of geometry around the central metal ion, MM distance, M-O-M bond angle and overlapping of magnetic orbitals on the magnetic exchange coupling are discussed.
authors.affiliation: Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA. ssmassoud@louisiana.edu.
authors.forename: Salah S
authors.initials: SS
authors.lastname: Massoud
authors.forename: Mark
authors.initials: M
authors.lastname: Spell
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Ledet
authors.forename: Thomas
authors.initials: T
authors.lastname: Junk
authors.forename: Radovan
authors.initials: R
authors.lastname: Herchel
authors.forename: Roland C
authors.initials: RC
authors.lastname: Fischer
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Trávníček
authors.forename: Franz A
authors.initials: FA
authors.lastname: Mautner