Naslov
Polymorphism in cobalt(II) and nickel(II) complexes with 6-bromopicolinic acid. Synthesis, structural and thermal studies

Autori
Kukovec, Boris-Marko ; Popović, Zora

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Insights into Coordination, Bioinorganic and Applied Inorganic Chemistry (Book of Abstracts) / Melnik, M. ; Segl'a, P. ; Tatarko, M. - Bratislava : Slovak University of Technology Press, 2009, 66-66

ISBN
978-80-227-3085-3

Skup
XXII. International Conference on Coordination and Bioinorganic Chemistry

Mjesto i datum
Smolenice, Slovačka, 07.06.2009. - 12.06.2009

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
polymorphism; nickel(II); cobalt(II); complexes; 6-bromopicolinic acid

Sažetak
Many metal complexes with hydroxy derivatives of picolinic acid were prepared and characterized due to their potential biological acivity e. g. insulin-mimetic activity. However, there are only two metal complexes with 6-bromopicolinic acid (6-BrpicH) described in the literature until now. We have prepared and characterized triclinic (1a) and monoclinic (1b) polymorphs of cobalt(II) complex with 6-bromopicolinic acid, [Co(6-Brpic)2(H2O)2] • 3H2O, and two pseudopolymorphs of nickel(II) complex with the same ligand, [Ni(6-Brpic)2(H2O)2] • 3H2O (2) and [Ni(6-Brpic)2(H2O)2] • H2O (3). Complexes 1a and 1b were prepared in aqueous solution by reaction of cobalt(II) acetate with 6-bromopicolinic acid. The pH value of the solution determines the type of the polymorph. Complex 2 was prepared similarly (by using nickel(II) nitrate) while complex 3 was obtained by spontaneous recrystallization of 2 in mother liquor during several months. Both cobalt(II) and nickel(II) ions are octahedrally coordinated by two 6-bromopicolinate ligands and two water molecules in cis position in all prepared complexes. The complexes have also been characterized by IR spectroscopy and thermal methods (TGA-DTA). The number of crystallized water molecules in the prepared complexes was confirmed by thermal methods.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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