title: EPR study of the electronic properties and weak exchange interactions in bis(L-phenylalaninamidato)Cu(II).
abstract: We performed EPR measurements in powder and single crystal samples of bis(L-phenylalaninamidato)Cu(II) (C18H22CuN4O2). We evaluated the crystal and molecular g-factors, and estimate an exchange interaction of 0.15 K< or = J(AB)/k < or =0.32 K between coppers spaced apart 6.24 A, transmitted through an amidate bridge Cu-O-C-N-Cu. An unusual line shape is observed in powder samples arising from the relative orientation of symmetry-related molecules in the structure. The dipolar interaction and the layered structure of the copper ions produce a strong temperature variation of the spectral shape when the copper spins are polarized by the applied magnetic field.
authors.affiliation: Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, and INTEC (CONICET-UNL), Santa Fe, Argentina.
authors.forename: N M
authors.initials: NM
authors.lastname: Casado
authors.forename: R A
authors.initials: RA
authors.lastname: Isaacson
authors.forename: R
authors.initials: R
authors.lastname: Calvo
mesh_terms: D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D009942:Organometallic Compounds / Q000737:chemistry*; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; C439351:bis(phenylalaninamidato)Cu(II); D010649:Phenylalanine; D003300:Copper