Dinuclear terephthalato-bridged copper(II) complexes: Syntheses, spectral and structural characterization, and magnetic properties

作者：Massoud SS^*; Mautner FA; Vicente R; Sweeney HN

来源：Inorganica Chimica Acta, 2006, 359(5): 1489-1500.

DOI：10.1016/j.ica.2005.10.047

• copper(II) complexes
• dinuclear complexes
• terephthalato bridged
• crystal structure
• magnetic behavior

Herein, we report the syntheses, spectral and structural characterization, and magnetic behavior of four new dinuclear terephthalato-bridged copper(II) complexes with formulae [Cu-2(trpn)(2)G(mu-tP)](ClO4)(2)center dot 2H(2)O (1), [Cu-2(aepn)(2)(mu-tp)(ClO4)(2)] (2), [Cu(2)Medpt)(2)(mu-aepn)(H2O)(2)](ClO4)(2) (3) and (Cu-2(Et(2)dien)(2)(mu-tP)(H2O)](ClO4)(2) (4) where tp = terephthalate dianion, trpn = tris(3-aminopropyl)-amin, aepn =N-(2-aminoethyl)-1,3-propanediamine, Medpt=3,3'-diamino-N-methyldipropylmine and Et(2)dien=N,N-diethyldiethylenetriamine. The structures of these complexes consist of two mu-tp bridging Cu(II) centers in a bis(monodentate) bonding fashion. The coordination geometry of the Cu(II) ions in these Compounds may be described as close to square-based pyramid (SP) with severe significant distortion towards trigonal bipyramid (TBP) stereochemistry in 1. The visible spectra of the complexes in aqueous solutions are in complete agreement with the assigned X-ray geometry around the Cu(II) centers. Also, the solid infrared spectral data for the stretching frequencies of the tp-carboxalato groups, the v(COO-) reveals the existence of bis(monodentate) coordination mode for the bridged terephthalate ligand. The susceptibility measurements at variable temperature over the range 2-300 K are reported. Despite the same bonding mode of the tp bridging ligand, there has been observed slight antiferromagnetic coupling for the compounds 1 and 4 with J values of -0.5 and -2.9 cm(3) K mol(-1), respectively, and very weak ferromagnetic Coupling for 2 and 3 with J values of 0.8 and 10.1 cm(3) K mol(-1) 1, respectively. The magnetic results are discussed in relation to other related mu-terephthalato dinuclear Cu(II) published compounds.

• 出版日期2006-3-20