X-RAY CRYSTAL-STRUCTURE AND ELECTRONIC-SPECTRUM OF THE COMPLEX [CO(C3H4N2)4(H2O)2](C6H4COSO2N)2

The title compound has been synthesized and its crystal structure determined at room temperature. The final R value is 0.032 for 3116 independent observed reflections with I greater-than-or-equal-to 3-sigma(I). The crystal structure consists of repeated [Co(im)4(H2O)2]2+ cations and non-coordinated saccharin anions. In the complex cation [Co(im)4(H2O)2]2+, the Co2+ is bonded to four nitrogen atoms originating from four imidazole molecules and two oxygen atoms originating from two water molecules with an approximately octahedral stereochemistry. The d-d transition electronic spectrum of the title compound is also reported and is explained perfectly with the scaling radial theory which we proposed.