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 ( 1 H and 13 C), 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 H ) peaks disappeared in the 1 H-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– H ⋯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 σ 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. Graphical Abstract The different dicobaloxime (1 – 6) and organodicobaloximes (7 – 12) have been synthesized for the first time. Their redox properties were investigated using cyclic voltammetric (CV) techniques in a DMSO solution. These dicobaloximes/organodicobaloximes have been used as homogeneous catalyst for synthesis of cyclic carbonates presence of DMAP as co-catalyst.