Self-assembly of the rigid rodlike ligand N,N′-4,4′-diphenylethynebis(oxamate) (dpeba) and Cu2+ ions affords a novel dinuclear copper(II) metallacyclophane (nBu4N)4[Cu2(dpeba)2]·4MeOH·2Et2O (1) featuring a very long intermetallic distance (r = 15.0 Å). Magnetic susceptibility measurements for 1 reveal a moderately weak but nonnegligible intramolecular antiferromagnetic coupling between the two metal centers across the double para substituted diphenylethynediamidate bridge (J = −3.9 cm−1; H = −JS1S2, where S1 = S2 = SCu = 1/2). Density functional electronic structure calculations on 1 support the occurrence of a spin polarization mechanism.
Very Long-Distance Magnetic Coupling in a Dinuclear Copper(II) Metallacyclophane with Extended π-Conjugated para-substituted Diphenylethyne Bridges
ARMENTANO, Donatella;DE MUNNO G;
2011-01-01
Abstract
Self-assembly of the rigid rodlike ligand N,N′-4,4′-diphenylethynebis(oxamate) (dpeba) and Cu2+ ions affords a novel dinuclear copper(II) metallacyclophane (nBu4N)4[Cu2(dpeba)2]·4MeOH·2Et2O (1) featuring a very long intermetallic distance (r = 15.0 Å). Magnetic susceptibility measurements for 1 reveal a moderately weak but nonnegligible intramolecular antiferromagnetic coupling between the two metal centers across the double para substituted diphenylethynediamidate bridge (J = −3.9 cm−1; H = −JS1S2, where S1 = S2 = SCu = 1/2). Density functional electronic structure calculations on 1 support the occurrence of a spin polarization mechanism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
