Dicobaloxime/organodicobaloximes bridged by different axial groups: synthesis, characterization, spectroscopy, and catalysis

In this study, the various ligands axially coordinated to two cobalt center bound to the N-4-oxime core in 12 new dicobaloxime/organodicobaloxime (1-12) complexes have been synthesized and characterized by NMR (H-1 and C-13), UV-Visible, FT-IR, LC-MS, molar conductivity analysis, melting point, and magnetic susceptibility experiments with elemental analysis. These spectroscopic results indicate that the formation of new dicobaloxime/organodicobaloxime (1-12) complexes. The (C=N-O Emphasis Type=ItalicUnderline H) peaks disappeared in the H-1-NMR spectrum of dicobaloxime/organodicobaloxime (1-12) complexes, while new peaks were observed at range 20.18-18.33 ppm, indicating that the groups of ligands have been transformed to intramolecular H-bridge (O-Emphasis Type=ItalicUnderline Hai overline O). The dicobaloxime (1-6) species give a better cyclic voltammogram as compared to its organodicobaloxime derivatives (7-12) due to cyclic voltammograms of the organodicobaloximes (7-12) were poor. This is possibly due to the enhanced sigma donation by R groups in the organocobaloximes which are substantially stabilized. The organodicobaloxime (10) showed much better catalytic activity compared to the other cobaoxime complexes.