Bonding mu(1,3)- (trans) vs mu(1,2)- (cis) in squarato-bridging dinuclear copper(II) complexes derived from pyridyl amine ligands

作者：Mautner Franz A^*; Mikuriya Masahiro; Naka Yuko; Louka Febee R; Massoud Salah S

来源：Polyhedron, 2015, 85: 110-116.

DOI：10.1016/j.poly.2014.08.040

• Copper
• Polynuclear complexes
• Squarato bridged
• Crystal structure
• Magnetic properties

A series of trans- and cis-dinuclear squarato-bridged copper(II) complexes [Cu-2(dpya)(4)(mu(1,3)-C4O4)](ClO4)(2)center dot MeOH (1), [Cu-2(bdmpzpy)(2)(mu(1,3)-C4O4)(H2O)(2)](ClO4)(2)center dot 5H(2)O (2) and [Cu-2(pmea)(2)(mu(1,2)-C4O4)](ClO4)(2)center dot 1.5H(2)O (3) derived from di-, tri- and tetra-dentate pyridyl amine ligands (C4O42- is the 3,4-dihydroxycyclobut-3-en-1,2-dione dianion = squarate dianion, dpya = di-2-pyridylamine, bdmpzpy = 2,6-bis[(2,5-dimethyl-1H-pyrazolyl)methyl]pyridine, pmea = bis(2-pyridylmethyl)-2-(2-pyridylethyl)amine) were synthesized and structurally characterized by single crystal X-ray crystallography. In this series, structures consist of the ClO4- groups as counter ions and the C4O42- is bridging two Cu(II) ions in a mu-1, 3-bis(monodentate) (1 and 2) and a mu-1,2-bis(monodentate) (3) bonding modes. The coordination environment around the Cu(II) centers in these complexes is a five-coordinate with a distorted square geometry where the intra-dinuclear Cu center dot center dot center dot Cu distances across the bridged squarato ligand are in the range 7.26-7.82 angstrom in the trans mu(1,3)- complexes 1 and 2, and 6.76 angstrom in the corresponding cis mu(1,2)- complex 3. The magnetic measurements in the 4.5-300 K temperature range reveal weak antiferromagnetic coupling in the three complexes (vertical bar J vertical bar = 2.4-12.4 cm(-1)).

• 出版日期2015-1-8