Article ID Journal Published Year Pages File Type
1313085 Inorganica Chimica Acta 2006 12 Pages PDF
Abstract

Herein, we report the syntheses, spectral and structural characterization, and magnetic behavior of four new dinuclear terephthalato-bridged copper(II) complexes with formulae [Cu2(trpn)2(μ-tp)](ClO4)2 · 2H2O (1), [Cu2(aepn)2(μ-tp)(ClO4)2] (2), [Cu2(Medpt)2(μ-tp)(H2O)2](ClO4)2 (3) and [Cu2(Et2dien)2(μ-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 Et2dien = N,N-diethyldiethylenetriamine. The structures of these complexes consist of two μ-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 ν(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 cm3 K mol−1, respectively, and very weak ferromagnetic coupling for 2 and 3 with J values of 0.8 and 10.1 cm3 K mol−1, respectively. The magnetic results are discussed in relation to other related μ-terephthalato dinuclear Cu(II) published compounds.

Graphical abstractFour new terephthalato-bridged copper(II) complexes with the formulae [Cu2(trpn)2(μ-tp)](ClO4)2 · 2H2O (1), [Cu2(aepn)2(μ-tp)(ClO4)2] (2), [Cu2(Medpt)2(μ-tp)(H2O)2](ClO4)2 (3) and [Cu2(Et2dien)2(μ-tp)(H2O)](ClO4)2 (4) were synthesized and structurally characterized, and their magnetic properties were studied.Figure optionsDownload full-size imageDownload as PowerPoint slide

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Physical Sciences and Engineering Chemistry Inorganic Chemistry
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