Long-range magnetic coupling through extended pi-conjugated aromatic bridges in dinuclear copper(II) metallacyclophanes.
Self-assembly of 1,4-phenylenebis(oxamate) and 4,4'-biphenylenebis(oxamate) ligands and Cu2+ ions gives two new dinuclear copper(II) metallacyclophanes where the two metal centers are connected by double para-substituted aromatic diamide bridges. Despite the relatively large intramolecular Cu-Cu distance of ca. 8 and 12 A for each complex, magnetic susceptibility measurements evidence strong to moderately strong intramolecular antiferromagnetic couplings (-J values of the order of 100 and 10 cm-1, respectively). Density functional theory calculations on these compounds and their homologues with linear oligo-p-phenylenediamide bridges predict a rather slow exponential decay of magnetic coupling with increasing intermetal distance (r values up to 25 A) along this novel series of dicopper metalla-amidocyclophanes.
Pardo
Emilio
E
Departament de Química Inorgànica, Instituto de Ciencia Molecular, Facultat de Química, Universitat de València, 46100 Burjassot, València, Spain.
Faus
Juan
J
Julve
Miguel
M
Lloret
Francesc
F
Muñoz
M Carmen
MC
Cano
Joan
J
Ottenwaelder
Xavier
X
Journaux
Yves
Y
Carrasco
Rosa
R
Blay
Gonzalo
G
Fernández
Isabel
I
Ruiz-García
Rafael
R