Some substituted urea and thiourea complexes of Co(II), Mn(II), and Cr(III)

Abstract

Complexes of Co(II), Mn(II), and Cr(III) with N-butylurea, N-methylthiourea, and N,N′-dimethylthiourea, and Cl−, Br−, NO3−, and ClO4− anions were prepared and characterized using infrared and visible spectroscopy, and magnetic susceptibility. The urea is bonded through oxygen, and the thioureas through sulfur in all cases. The Co–N-butylurea compounds are octahedral, mostly with CoL6X2 stoichiometries, but some compounds involving coordinated anions and possibly bridging butylurea ligands were found. The Co–thioureas are tetrahedral. Octahedral Cr(III) compounds of the type CrL3X3 and CrL6(ClO4)3 were prepared, and the CrS6 chromophore characterized. Mn(II)–butylureas are octahedral, while the thioureas show MnL6X2 and MnL4X2 stoichiometries. X-ray diffraction established some of the latter to be isostructural with the analogous tetrahedral Co(II) compounds. Ligand field parameters Dq and B have been evaluated for the Co(II) and Cr(III) compounds.