Naslov
Preparation, structural and thermal characterization of cobalt(II) and copper(II) complexes with 3-hydroxypicolinamide

Autori
Đaković, Marijana ; Kukovec, Boris-Marko ; Popović, Zora

Izvornik
Transition metal chemistry (0340-4285) 36 (2011), 1; 65-71

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

Ključne riječi
cobalt(II); copper(II); 3-hydroxypicolinamide; crystal structure; TG/DTA methods

Sažetak
Cobalt(II) and copper(II) complexes of 3-hydroxypicolinamide (3-OHpia), namely [Co(3-OHpia)2(H2O)2](NO3)2 (1), [Co(3-Opia)2(H2O)2] (2) and [Cu(3-OHpia)2(NO3)2] (3) were prepared and characterized by IR spectroscopy and TG/DTA methods. The molecular and crystal structures of 1 and 3 were determined by X-ray crystal structure analysis. Complexes 1 and 3 were obtained by a reaction of 3-hydroxypicolinamide with cobalt(II) nitrate or copper(II) nitrate, respectively, in a mixture of ethanol and water. Complex 2 was prepared by a reaction of cobalt(II) acetate and 3-OHpia in aqueous solution. X-Ray structural analysis revealed octahedron as a coordination polyhedron in both 1 and 3 and the same N, O-chelated coordination mode of 3-OHpia. The coordination sphere of cobalt(II) ion in 1 is completed by two coordinated water molecules and of copper(II) ion in 3 by two coordinated nitrate anions. There are also two uncoordinated nitrate ions in 1 which compensate the positive charge of cobalt(II). The crystal structures of 1 and 3 are dominated by intermolecular O–H...O and N–H...O hydrogen bonds. The thermogravimetric study indicated the loss of two coordinated water molecules in 1 and 2 and of one 3-OHpia ligand together with N2 molecule in 3 at lower temperatures (up to 300 °C).

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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