| Autor: |
Saravanakumar, Duraisamy, Sengottuvelan, Nallathambi, Narayanan, Vengidusamy, Kandaswamy, Muthusamy, Chinnakali, Kandaswamy, Senthilkumar, Gopal, Fun, Hoong Kun |
| Zdroj: |
European Journal of Inorganic Chemistry; February 2004, Vol. 2004 Issue: 4 p872-878, 7p |
| Abstrakt: |
The new binuclear copper(II) complexes Cu2L1−3 and [Cu2L4,5](ClO4)2 were synthesized by reaction of the monomeric cis-N,N'-bis(3-aminopropyl)oxamidatocopper(II) complex [Cu(oxpn)] with acetylacetone, benzoylacetone, salicylaldehyde, 2-pyridinecarboxaldehyde and diacetyl monoxime in the presence of copper(II) acetate or perchlorate owing to the trans isomerisation of the cis-oxamidato complex. The crystal structure of Cu2L1 consists of centrosymmetric binuclear copper(II) ions which are bridged by an oxamidato group in the trans conformation with a copper−copper distance of 5.121 Å. Each copper(II) ion occupies an inner site of the N2O2 donor with a distorted square-planar environment. Electrochemical studies showed that two quasireversible one-electron reduction waves are obtained in the cathodic region (E1pc = −0.48 to −1.02 V, E2pc = −1.08 to −1.34 V). The conproportionation constants Kcon for the mixed-valence CuICuII complexes have been determined electrochemically. Room-temperature magnetic-moment studies of binuclear copper(II) complexes reveal the presence of a strong antiferromagnetic interaction (μeff = 1.14−1.24 μB) which is also observed from the broad spectra with g = 2.1. A variable-temperature magnetic-susceptibility study of the complexes 1 and 4 gives J values of −510 cm−1 and −497 cm−1 respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) |
| Databáze: |
Supplemental Index |
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