The cobalt(II) complexes dichloro[2-(3,4-dichlorophenyl)imino-kappaN-N-(2-thiazolin-kappaN-2-yl)thiazohdine]cobalt(II) (1) and dichloro[2-(3,4-dichlorophenyl)imino-kappaN-N-(2-thiazin-kappaN-2-yl)thiazolidine]cobalt(II) (2) have been isolated and characterized in the solid state by X-ray diffraction, elemental analysis, IR spectra, magnetic measurements and UV-Vis-NIR diffuse. reflectance spectroscopy. In both complexes, the environment around the cobalt(II) ion may be described as a distorted tetrahedral geometry, with the metallic atom coordinated to two chlorine atoms [Co-Cl(1) = 2.213(1) Angstrom; Co-Cl(2) = 2.226(1) Angstrom], one imino nitrogen [Co-N(3) = 1.992(2) Angstrom] and one thiazoline nitrogen [Co-N(1) = 1.974(2) Angstrom] in complex 1 and to two chlorine atoms [Co-Cl(1) = 2.244(2) Angstrom; Co-Cl(2) = 2.226(1) Angstrom], one imino nitrogen [Co-N(3) = 1.970(4) Angstrom] and one thiazine nitrogen [Co-N(1) = 1.946(4) Angstrom] in complex 2. (C) 2004 Elsevier Ltd. All rights reserved.