Structural, Spectroscopic, and Thermal Decomposition Features of [Carbonatotetraamminecobalt(III)] Iodide—Insight into the Simultaneous Solid-Phase Quasi-Intramolecular Redox Reactions

[κ2-O,O′-Carbonatotetraamminecobalt(III)] iodide, or [Co(NH3)4CO3]I, named in this paper as compound 1, was prepared and characterized comprehensively with spectroscopic (IR, Raman UV) single-crystal X-ray diffraction methods. Compound 1 orthorhombic, isomorphous the analogous bromide. The four ammonia ligands carbonate anion were coordinated to central cobalt cation a distorted octahedral geometry. ion formed four-membered symmetric planar chelate ring. complex cations bound each other by N-H···O hydrogen bonds zigzag sheets via an extended 2D bond network. iodide ions arranged into pairs its pair through three bonds. thermal decomposition started oxidation of CoIII solid phase resulting [Co(NH3)4CO3] I2. This intermediate CoII-complex situ decomposed Co3O4 C-N containing intermediates. In inert atmosphere, CO compounds, also, due CoCO3 intermediate, formed. quasi-intramolecular solid-phase redox reaction might have resulted formation compounds substoichiometric release CO2 from 1. intermediates reduced CoO Co, whereas oxygen-containing end-product Co3O4, even at 200 °C, endothermic ligand loss coincided consecutive exothermic processes.