Structural characterization of a thiazoline-pyrazole ligand and its complexes with cobalt(II) and copper(II)

Abstract

The structural characterization of 2-(pyrazol-1-yl)-2-thiazoline (PyTn) is reported. The complexes dichlorobis[2-(pyrazol-1-yl-κ N)-2-thiazoline-κ N]cobalt(II)-water (1/2) ( 1) and di-μ-chloro-bis{chloro[2-(pyrazol-1-yl-κ N)-2-thiazoline-κ N]}copper(II) ( 2) have been isolated and characterized through elemental analysis, IR, UV–Vis–NIR diffuse reflectance, X-ray diffraction and magnetic susceptibility, as well as, in the case of 2, by means of EPR. The environment around cobalt atom in 1 may be described as a distorted octahedron with the metallic atom coordinated to two thiazoline nitrogen atoms [Co–N(1) = 2.097(2) Å], two pyrazole nitrogen atoms [Co–N(3) = 2.157(2) Å] and two chloride ions [Co–Cl(1) = 2.472(1) Å]. With regard to 2, it can be said that its structure consists of dimeric [Cu 2Cl 4L 2] molecules in which copper ions are bridged by two chloro ligands. The geometry about each copper ion approximates to a distorted square pyramid with each copper atom coordinated to one thiazoline nitrogen atom [Cu–N(1) = 2.012(2) Å], one pyrazole nitrogen atom [Cu–N(3) = 1.995(2) Å], one terminal chloro ligand [Cu–Cl(1) = 2.254(1) Å] and two bridging chloro ligands [Cu–Cl(2) = 2.218(1) Å, Cu–Cl(2a) = 2.906(1) Å].