Encapsulation of halocadmate anion via hydrogen bonding: synthesis and characterization of bis(diethylenetriamine)cobalt(III) complex containing hexabromocadmate anion

In this work, the encapsulation of [CdBr(6)](4−) by six cations, [Co(dien)(2)](3+) has been described with the help of single crystal X-ray structural study in the complex, mer-[Co(dien)(2)](2)[CdBr(6)]Br(2). The complex anion, [CdBr(6)](4−) has been obtained through solution method while attempting to synthesize complex dianion, [CdBr(4)](2−). This newly synthesized complex has been initially characterized by elemental analyses and spectroscopic studies (IR, NMR and UV-Visible). IR and NMR studies have been used for the isomeric identification of [Co(dien)(2)](3+). Single crystal X-ray structure determination has revealed the presence of two complex cations, [Co(dien)(2)](3+), one complex anion, [CdBr(6)](4−), and two Br(−) anions. The complex has crystallized in monoclinic crystal system with space group, P2(1)/n. The study of intermolecular interactions has confirmed the stability of crystal structure through N-H type H-bonding interactions besides electrostatic forces of attraction.