Silicon containing new salicylaldimine Pd(II) and Co(II) metal complexes as efficient catalysts in transformation of carbon dioxide (CO2) to cyclic carbonates

Chemical fixation of CO2into cyclic carbonates by azo-containing Schiff base metal complexes

“…Due to the great properties, chemical fixation of CO 2 becomes more and more important for decrease of carbon emission day by day 4 . 30 The most important carbon dioxide fixation products are cyclic carbonates which widely used as monomer for polymer synthesis, aprotic solvents, antifoam additives or plasticizers [5][6][7][8][9][10] . Cyclic carbonates can be synthesized via coupling reaction between CO 2 and strained heterocycles, though hard reaction conditions and 35 often a suitable catalyst should be used 11 .…”

“…Among the synthesized catalysts such as alkali metal salts, 40 transition metal complexes, Schiff Bases and ionic liquids, metal complexes based on transition metal complexes have been of great interest. We have found out that only a few metals such as Al, Cr, Co, Mg, Li, Zn, Cu and Cd are effective for coupling of CO 2 and epoxides 9 . In recent studies, it is mentioned that 45 transition metals Ni, Rh, Pd and Au can catalyze the same reaction 13 .…”

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

“…were determined in previous studies [28][29][30]. The cobaloxime complexes (1-10), when 4-dimethylamino pyridine (DMAP) was used as co-catalysts, showed catalytic activity and selectivity for the conversion of CO 2 into cyclic carbonates using epoxide derivatives as substrate and solvent.…”

“…1 H NMR (DMSO-d 6 , TMS, 300 MHz, δ ppm): 18.36 and 18.16 (s, 2H, O-H⋯O), 8. 90 (s, 2H, HC=N), 8.11 (s, 4H, Ar-CH), 7.62-7.21 (m, 13H, Ar-CH), 5.46 (s, 2H, Ph-CH 2 ), 2.52 (s, 4H, CH 3 -CH 2 ), 1.19 (t, 9H, J = 9.2 Hz, t-BuPy-CH 3 ) and 1.05 (s, 6H, CH 3 -CH 2 ), 13 C NMR (DMSO-d 6 , TMS, 75 MHz, δ ppm): 152.45 and 148.96 (C=NOH), 148.03, 146.23, 145.08, 140.86, 137.01, 132.15, 130.28, 129.64, 128.46 and 128.39 (Ar-CH), 78.43 (CH 2 -Ph), 36.29 (t-BuPy-C-CH 3 ),29.91 (t-BuPy-C-CH 3 ), 28.99 (CH 3 -CH 2 ), and 16.04 (CH 3 -CH 2 ). UV-vis (λ max , nm, * = shoulder peak): 266 and 381* (C 2 H 5 OH); 236, 265, and 381* (CH 2 Cl 2 ).2.4.…”

Highly efficient conversion of CO2 at atmospheric pressure to cyclic carbonates with in situ-generated homogeneous catalysts from a copper-containing coordination polymer

“…DMAP [23,24], ionic liquids [25], triamines [26], and metal halides [27,28] have been widely reported as co-catalysts. However, only Bu 4 NBr was found to be a suitable co-catalyst for atmospheric pressure catalytic systems.…”