Naslov
3D supramolecular architectures of copper(II) complexes with 6-methylpicolinic and 6-bromopicolinic acid. Synthesis, spectroscopic, thermal and magnetic properties

Autori
Kukovec, Boris-Marko ; Popović, Zora ; Kozlevčar, Bojan ; Jagličić, Zvonko

Izvornik
Polyhedron (0277-5387) 27 (2008), 18; 3631-3638

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
copper(II) complexes; carboxylate ligands; π -π interactions; EPR spectroscopy; magnetic properties; thermal methods (TGA/DTA)

Sažetak
Copper(II) complexes of 6-methylpicolinic (6-MepicH) and 6-bromopicolinic acid (6-BrpicH), namely [Cu(6-Mepic)2(H2O)] (1), [Cu(6-Mepic)2(py)] (2) and [Cu(6-Brpic)2(H2O)] (3) were prepared and characterized by spectroscopic methods (IR, EPR). Their molecular and crystal structures were determined by X-ray crystal structure analysis, their thermal stability by TGA/DTA methods, while their magnetic properties were elucidated by the measurement of the magnetic susceptibility. X-Ray structural analysis revealed an intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedron in 1 and 3 and a trigonal-bipyramidal one in 2 with the same N, O-chelated coordination mode for both 6-MepicH and 6-BrpicH in 1− 3. EPR spectra showed three different types of copper(II) S = ½ ; ; symmetry signals. Most probably they could be assigned to the elongated axial in 1, the isotropic in 2 and the rhombic in 3. Both 1 and 2 showed the paramagnetic behaviour, while 3 exhibited an antiferromagnetic interaction, ascribed to the formation of 'pseudo' binuclear units by the π -π stacking between pyridine rings.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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