| Autor: |
Montserrat Corbella, Prasanta Bhowmik, Shouvik Chattopadhyay, Verónica Gómez, Núria Aliaga-Alcalde |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Polyhedron. 49:269-276 |
| ISSN: |
0277-5387 |
| Popis: |
Tetranuclear [Cu4(L1)2(HL1)2(H2O)](ClO4)2·2H2O (1) and binuclear [Cu2(L2)2]·CH3OH (2) compounds are prepared and the molecular structures elucidated on the basis of X-ray crystallography [H2L1 = 2-[(2-hydroxy-ethylimino)-methyl]-6-methoxy-phenol, H2L2 = 2-[(3-hydroxy-propylimino)-methyl]-6-methoxy-phenol]. Compound 1 is made up of the cation [Cu4(L1)2(HL1)2(H2O)2]2+ and two ClO4− anions which are H-bonded to the cation. The four Cu(II) atoms are not crystallographically equivalent, among then two are in tetragonal [CuNO5] geometries and the rest two are in square pyramidal geometries. The asymmetric unit of compound 2 consists of one neutral [Cu2(L2)2] moiety and a methanol molecule. Each copper atom in compound 2 has a four-coordinate square-planar environment. Compound 1 can be described as an open cage with a [Cu4(μ3-Oal)2(μ2-Oph)2]4+ core (al = alkoxido and ph = phenoxido). Variable temperature solid state magnetic studies between 2–300 K were carried out and the data indicate predominant antiferromagnetic exchange interactions and a spin ground state S = 0. The data were fitted with an average J value model, using the spin Hamiltonian H = −Jav(S1·S2 + S3·S4 + S1·S3 + S2·S4). The best fit was obtained with Jav = −99.0 cm−1. The magnetic properties of compound 2 have also been analyzed and the data show a large antiferromagnetic interaction, in agreement with the [Cu2(μ2-Oal)2]2+ core. The best fit of the data was obtained with J = −891 cm−1 (H = −J S1·S2). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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