Theoretical description of the magnetic properties of mu(3)-hydroxo bridged trinuclear copper(II) complexes
A theoretical study of the magnetic properties, using density functional theory, of a family of trinuclear mu(3)-OH copper(II) complexes reported in the literature is presented. The reported X-ray crystal structures of [Cu-3(mu(3)-OH)(aat)(3)(H2O)(3)](NO3)(2)center dot H2O (HUKDUM), where aat: 3-acetylamine-1,2,4-triazole; [Cu-3(mu(3)-OH)(aaat)(3)(H2SO4)(HSO4)(H2O)] (HUKDOG), where aaat: 3-acetylamine-5-amine-1,2,4-triazole; [Cu-3(mu(3)-OH)(PhPyCNO)(3)(tchlphac)(2)] (HOHQUR), where PhPyCNO: phenyl 2-pyridyl-ketoxime and tchlphac: acid 2,4,5-trichlorophenoxyacetic; [Cu-3(mu(3)-OH)(PhPyCNO)(3)(NO3)(2)(CH3OH)] (ILEGEM); [Cu-3(mu(3)-OH)(pz)(3)(Hpz)(3)(ClO4)(2)] (QOPJIP), where Hpz = pyrazole; [Cu-3(mu(3)-OH)(pz)(3)(Hpz)(Me3CCOO)(2)]a (TM) 2Me(3)CCOOH (DEFSEN) and [Cu-3(mu(3)-OH)(8-amino-4-methyl-5-azaoct-3-en-2-one)(3)][CuI3] (RITXUO), were used in the calculations. The magnetic exchange constants were calculated using the broken-symmetry approach. The calculated J values are for HUKDUM J(1) = -68.6 cm(-1), J(2) = -69.9 cm(-1), J(3) = -70.4 cm(-1); for HUKDOG, J(1) = -73.5 cm(-1), J(2) = -58.9 cm(-1), J(3) = -62.1 cm(-1); for HOHQUR J(1) = -128.3 cm(-1), J(2) = -134.1 cm(-1), J(3) = -120.4 cm(-1); for ILEGEM J(1) = -151.6 cm(-1), J(2) = -173.9 cm(-1), J(3) = -186.9 cm(-1); for QOPJIP J(1) = -118.3 cm(-1), J(2) = -106.0 cm(-1), J(3) = -120.6 cm(-1); for DEFSEN J(1) = -74.9 cm(-1), J(2) = -64.0 cm(-1), J(3) = -57.7 cm(-1) and for RITXUO J(1) = -10.9 cm(-1), J(2) = +14.3 cm(-1), J(3) = -35.4 cm(-1). The Kahn-Briat model was used to correlate the calculated magnetic properties with the overlap of the magnetic orbitals. Spin density surfaces show that the delocalization mechanism is predominant in all the studied compounds.
kahn-briat cu-ii dft hydroxo-centered trinuclear complex