ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Dicobaloxime/organodicobaloximes bridged by different axial groups: synthesis, characterization, spectroscopy, and catalysis
Ahmet Kilic, Hamza Fırat, Emine Aytar, Mustafa Durgun, Aysegul Kutluay Baytak, Mehmet Aslanoglu, and Mahmut Ulusoy
Department of Chemistry, Faculty of Arts and Sciences, Harran University, Şanlıurfa, Turkey
Abstract: In this study, the various ligands axially coordinated to two cobalt center bound to the N4-oxime core in 12 new dicobaloxime/organodicobaloxime (1–12) complexes have been synthesized and characterized by NMR (1H and 13C), 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–OH) peaks disappeared in the 1H-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.
Keywords: Co(III) complexes; Dicobaloxime; Organodicobaloxime; Cyclic voltammetry; Cyclic carbonates; CO2 fixation; Reaction parameters
Full paper is available at www.springerlink.com.
Chemical Papers 71 (9) 1705–1720 (2017)
Saturday, February 29, 2020