title: A density functional theory study of the magnetic exchange coupling in dinuclear manganese(II) inverse crown structures.
abstract: The magnetic exchange coupling constants between two Mn(II) centers for a set of five inverse crown structures have been investigated by means of a methodology based on broken-symmetry unrestricted density functional theory. These novel and highly unstable compounds present superexchange interactions between two Mn centers, each one with S = 5/2 through anionic "guests" such as oxygen, benzene, or hydrides or through the cationic ring formed by amide ligands and alkali metals (Na, Li). Magnetic exchange couplings calculated at B3LYP/6-31G(d,p) level yield strong antiferromagnetic couplings for compounds linked via an oxygen atom or hydride and very small antiferromagnetic couplings for those linked via a benzene molecule, deprotonated in either 1,4- or 1,3- positions. Analysis of the magnetic orbitals and spin polarization maps provide an understanding of the exchange mechanism between the Mn centers. The dependence of J with respect to 10 different density functional theory potentials employed and the basis set has been analyzed.
authors.affiliation: Departament de Química Física i Analítica, Universitat Jaume I, 12071, Castelló, Spain.
authors.forename: Ederley
authors.initials: E
authors.lastname: Vélez
authors.forename: Antonio
authors.initials: A
authors.lastname: Alberola
authors.forename: Víctor
authors.initials: V
authors.lastname: Polo
mesh_terms: D019281:Dimerization; D006859:Hydrogen / Q000737:chemistry; D008280:Magnetics; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D008345:Manganese; D006859:Hydrogen