Azido- and thiocyanato-cobalt(II) complexes based pyrazole ligands

The reactions of pyrazole based ligands with Co(II) salts in the presence of NaN3 or NH4NCS afforded the cationic–anionic complexes [Co(bdmpzpy)2][Co(N3)4] (1) and [Co(bdmpzpy)2][Co(NCS)4].2CH3NO2 (2) containing tetrathiocyanato- and tetraazido-Co(II) complex anions as well as the mononuclear complexes [Co(bepza)(NCS)2] (3), [Co(tedmpza)(NCS)]ClO4·½H2O (4) and [Co(tedmpza)(N3)]ClO4·H2O (5) where bdmpzpy = 2,6-bis[(3,5-dimethyl-pyrazol-1H-yl)-methyl]pyridine, bepza = bis(ethyl-pyrazol-1H-yl)amine and tedmpza = tris(3,5-dimethyl-ethyl-pyrazol-1H-yl)amine. The complexes were structurally characterized by elemental microanalyses, IR and UV–Vis spectroscopy and by single crystal X-ray crystallography.

A new series of mononuclear thiocyanato- and azido-Co(II) as well as anionic–cationic cobalt(II) complexes containing tetrathiocyanato and tetraazido complex anions were synthesized from pyrazole based ligands. The molecular geometries of the complexes were structurally characterized.Figure optionsDownload as PowerPoint slide