title: Two temperature-independent spinomers of the dinuclear Mn(III) compound [{Mn(H(2)O)(phen)}(2)(mu-2-ClC(6)H(4)COO)(2)(mu-O)](ClO(4))(2).
abstract: Two spin isomers or spinomers of [{Mn(H(2)O)(phen)}(2)(mu-2-ClC(6)H(4)COO)(2)(mu-O)](ClO(4))(2) have been synthesized, characterized, and theoretically analyzed. The thermodynamically most stable, compound 1, shows a spin ground state S = 4, while the kinetically most favorable, compound 2.H(2)O, shows a spin ground state S = 0. Compound 1 exhibits ferromagnetic behavior, with J = 2.7 cm(-1), |D(Mn)| = 2.06 cm(-1), |E(Mn)| = 0.69 cm(-1), and zJ' = -0.11 cm(-1). Because of the anisotropy of the Mn(III) ions, the ground state S = 4 shows zero-field splitting (ZFS) with |D(4)| = 0.51 cm(-1), appreciably smaller than the D value for the single ion (D(Mn)), due to the relative orientations of the Jahn-Teller axes of both Mn(III) ions, which are quite perpendicular (102 degrees ). Compound 2.H(2)O shows antiferromagnetic coupling, with J = -12.6 cm(-1) (H = -JS(1).S(2) for both compounds). The formation of two spinomers has been explained by density functional theory (DFT) studies, which show that the stability of these compounds and their magnetic interaction are very sensitive to the rotation of the phenyl ring with respect to the carboxylate group of the 2-ClC(6)H(4)COO bridging ligand.
authors.affiliation: Departament de Química Inorgànica, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Gómez
authors.forename: Montserrat
authors.initials: M
authors.lastname: Corbella
authors.forename: Gabriel
authors.initials: G
authors.lastname: Aullón
mesh_terms: D000941:Antigens; D002245:Carbon Dioxide / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D016207:Cytokines / Q000737:chemistry*; D015195:Drug Design; D004563:Electrochemistry / Q000379:methods; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry; D006997:Hypochlorous Acid / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010100:Oxygen / Q000378:metabolism*; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013499:Surface Properties; D013696:Temperature
chemical_list: D000941:Antigens; D002264:Carboxylic Acids; D016207:Cytokines; D005290:Ferric Compounds; D008024:Ligands; C121169:cardiotrophin-like cytokine; C001215:ferrite; D002245:Carbon Dioxide; C041069:carboxyl radical; D006997:Hypochlorous Acid; D010100:Oxygen