title: Synthesis, structures, and physical properties of copper(II)-gadolinium(III) complexes combining ferromagnetic coupling and quadratic nonlinear optical properties.
abstract: Two copper(II)-gadolinium(III) metal complexes of formula CuIIGdIIILX3 are reported. H2L stands for the Schiff base ligand obtained by condensation of 3,4-dimethoxysalicylaldehyde with ethylenediamine (complex 1) or 1R,2R-(+)-1,2-diphenylethylenediamine (complex 2). While 1 reveals a centrosymmetric crystal structure, 2 crystallizes in the noncentrosymmetric P212121 space group and exhibits an efficiency 0.3 time that of urea in second harmonic generation. Due to a trend for dissociation in solution, the molecular hyperpolarizabilities (beta) cannot be determined experimentally for 1 and 2. Nevertheless, the electric field induced second harmonic (EFISH) technique, in connection with spectroscopic data and a ZINDO semiempirical approach, leads to a beta value of -6.5 x 10(-30) cm5 esu(-1), for the related CuIIL monomers, as an indicative range of magnitude in all these Schiff base complexes. In addition, 1 and 2 exhibit a ferromagnetic coupling in solid state with J = 3.3 and 1.3 cm-1, respectively (J being the parameter of the exchange Hamiltonian = -JSCu x SGd).
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, 205 route de Narbonne, 31077 Toulouse, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Margeat
authors.forename: Pascal G
authors.initials: PG
authors.lastname: Lacroix
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Costes
authors.forename: Bruno
authors.initials: B
authors.lastname: Donnadieu
authors.forename: Christine
authors.initials: C
authors.lastname: Lepetit
authors.forename: Keitaro
authors.initials: K
authors.lastname: Nakatani