Source:http://linkedlifedata.com/resource/pubmed/id/17213932
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| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2007-1-10
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| pubmed:abstractText |
Dicopper(II) complexes of two new 3,5-disubstituted-pyrazole-based ligands, bis(quadridentate) macrocyclic ligand (L1)(2-) and bis(terdentate) acyclic ligand (L2)(-), were synthesised by Schiff base condensation of 3,5-diformylpyrazole and either one equivalent of 1,3-diaminopropane or two equivalents of 2-(2-aminoethyl)pyridine in the presence of one or two equivalents of copper(II) ions, respectively. Copper(II) acetate monohydrate was employed in the synthesis of [Cu(2)(L1)(OAc)(2)], [Cu(2)(L2)(H(2)O)(2)(OAc)(3)] and [Cu(II)(2)(L1)(NCS)(2)]; in the last of these one equivalent of NaNCS per copper(II) ion was also added. The fourth complex, [Cu(2)(L2)(NCS)(2)(DMF)]BF(4), was prepared using copper(II) tetrafluoroborate hexahydrate, along with two equivalents of NaOH and six of NaSCN. All four of these dimetallic complexes have been characterised by single crystal X-ray diffraction: the two macrocyclic complexes are the first such Schiff base complexes to be so characterised. A feature common to all four of the structures is bridging of the two copper(II) centres by the pyrazolate moiety/moieties. The structure determinations show that the coordination mode of the acetate groups in both [Cu(2)(L1)(OAc)(2)].2MeOH.H(2)O and [Cu(2)(L2)(H(2)O)(2)(OAc)(3)] is unidentate as had been tentatively predicted by analysis of the infrared spectra (DeltaOCO of 199 and 208 cm(-1), respectively). The magnetochemical studies of the macrocyclic complexes, over the temperature range 4-300 K, revealed strong antiferromagnetic coupling with J = -169 and -213 cm(-1) for [Cu(2)(L1)(OAc)(2)].2H(2)O and [Cu(II)(2)(L1)(NCS)(2)].DMF respectively. The J values have been discussed in relation to a published correlation involving the CuN(pyrazolate)N(pyrazolate) angles.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Jan
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| pubmed:issn |
1477-9226
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
28
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
467-75
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| pubmed:year |
2007
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| pubmed:articleTitle |
Dicopper(II) complexes of a new pyrazolate-containing Schiff-base macrocycle and related acyclic ligand.
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| pubmed:affiliation |
Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.
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| pubmed:publicationType |
Journal Article
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