Synthesis, characterization, and thermal properties of cobalt(II) compounds with guanidinate ligands

Two cobalt(ii) guanidinate compounds of the general type [((R)(2)NC((PrN)-Pr-i)(2))(2)Co] (R = Me, SiMe3) were synthesized and characterized by elemental analysis, H-1 NMR, and single crystal X-ray diffraction. The compounds were easily synthesized using a conventional salt-elimination reaction of CoCl2 with the corresponding lithium salt of guanidinate ligands in a general procedure. The thermal properties of the compounds including their volatility, vapour pressure, and thermal stability were studied by thermogravimetric analysis (TGA). The results indicated that both compounds volatilized in a single step with residual mass remaining (13.2% and 10.5%). Moreover, the compounds that were potentially CVD precursors were investigated through deposition experiments conducted in a hot-wall CVD reactor. A film was successfully deposited through CVD, which indicated that the compounds were capable of being precursors for the CVD of cobalt-based films.