Wydział Chemii

Aleksander Kufelnicki

Jolanta Jaciubek-Rosińska

Marta Sobiesiak

Agata Paneth

Julia Jezierska

Elżbieta Budzisz

2017

Zeitschrift für Anorganische und Allgemeine Chemie

643

1067-1074

10.1002/zaac.201700102

Naukowa

Angielski

Artykuł

The study reports the synthesis of complexes Co(HL)Cl₂ (1), Ni(HL)Cl₂ (2), Cu(HL)Cl₂ (3), and Zn(HL)₃Cl₂ (4) with the title ligand, 5-(pyrazin-2-yl)-1,2,4-triazole-5-thione (HL), and their characterization by elemental analyses, ESI-MS (m/z), FT-IR and UV/Vis spectroscopy, as well as EPR in the case of the Cu^II complex. The comparative analysis of IR spectra of the metal ion complexes with HL and HL alone indicated that the metal ions in 1, 2, and 3 are chelated by two nitrogen atoms, N(4) of pyrazine and N(5) of triazole in the thiol tautomeric form, whereas the Zn^IIion in 4 is coordinated by the non-protonated N(2) nitrogen atom of triazole in the thione form. pH potentiometry and UV/Vis spectroscopy were used to examine Co^II, Ni^II, and Zn^II complexes in 10/90 (v/v) DMSO/water solution, whereas the Cu^II complex was examined in 40/60 (v/v) DMSO/water solution. Monodeprotonation of the thione triazole in solution enables the formation of the L:M = 1:1 species with Co^II, Ni^II and Zn^II, the 2:1 species with Co^II and Zn^II, and the 3:1 species with Zn^II. A distorted tetrahedral arrangement of the Cu^II complex was suggested on the basis of EPR and Vis/NIR spectra.

s ligand, divalent metals, spectroscopic and equilibrium studies, synthesis design

http://dx.doi.org/10.1002/zaac.201700102

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