title: Synthesis, crystal structure, magnetic properties, and theoretical studies of [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] (mepirizole=4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine; pz=pyrazolate), a novel mu-pyrazolato-mu-hydroxo-dibridged copper(II) complex.
abstract: A novel mu-pyrazolato-mu-hydroxo-dibridged copper(II) complex has been synthesized and structurally characterized: [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] (mepirizole=4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine; pz=pyrazolate). The title compound crystallizes in the monoclinic system, space group P2(1)/c, with a=15.618(2) A, b=15.369(3) A, c=16.071(3) A, and beta=112.250(1) degrees. The structure is built up of dinuclear [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] units with five-coordinated copper(II) ions (CuBrN3O chromophores) linked by mu2-OH and mu2-pyrazolato bridges that are well separated from each others. The intramolecular copper-copper distance is 3.378(3) A. Magnetic susceptibility data show that the copper atoms are strongly antiferromagnetically coupled with J=-770 cm(-1). The obtained triplet-singlet energy gap is compared with those reported for a series of related dimers. The strong antiferromagnetic coupling arising from the complementarity of the hydroxo and pyrazolato bridges has been discussed on the basis of DFT calculations.
authors.affiliation: Departament de Química Inorgànica, Universitat de València, c/Vicent Andrés Estellés, s/n, 46100 Burjassot (València), Spain. escriva@uv.es
authors.forename: Emilio
authors.initials: E
authors.lastname: Escrivà
authors.forename: Julia
authors.initials: J
authors.lastname: García-Lozano
authors.forename: José
authors.initials: J
authors.lastname: Martínez-Lillo
authors.forename: Hugo
authors.initials: H
authors.lastname: Nuñez
authors.forename: Juan
authors.initials: J
authors.lastname: Server-Carrió
authors.forename: Lucía
authors.initials: L
authors.lastname: Soto
authors.forename: Rosa
authors.initials: R
authors.lastname: Carrasco
authors.forename: Joan
authors.initials: J
authors.lastname: Cano
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D018360:Crystallography, X-Ray; D004840:Epirizole / Q000737:chemistry*; D007202:Indicators and Reagents; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular
chemical_list: D007202:Indicators and Reagents; D008024:Ligands; D004840:Epirizole; D007501:Iron