The synthesis, characterization, and electrochemistry of molecular cobaloxime/organocobaloxime: catalysts for cycloaddition of carbon dioxide and epoxides

In this paper, the new cobaloxime (1), organocobaloxime (2) and multinuclear cobaloximes (3-10) were synthesized and characterized. These compounds were used as homogeneous catalysts for cyclic carbonate synthesis from carbon dioxide (CO2) and epoxides. The new cobaloxime (1), organocobaloxime (2), and their intramolecular hydrogen (O-H center dot center dot center dot O) bridges replaced by Cu(II)-containing multinuclear cobaloximes (3-10) were synthesized and characterized by elemental analysis, H-1 and C-13 NMR spectra, FT-IR spectra, UV-vis spectra, LC-MS spectra, molar conductivity measurements, melting point measurements, and magnetic susceptibility measurements. Their electrochemical properties were investigated using cyclic voltammetric techniques in DMSO solution. The cobaloxime or organocobaloxime (1, 2) were used as precursors, replacing intramolecular O-H center dot center dot center dot O bridges, forming multinuclear complexes (3-10). Then, these compounds were used as homogeneous catalysts for cyclic carbonate synthesis from carbon dioxide (CO2) and epoxides. In the catalytic experiments, dimethyl amino pyridine (DMAP) was used as cocatalyst, since DMAP was a more active base with higher yield compared to other Lewis bases. It is not necessary to use solvent according to catalytic test results, important in green chemistry.