Chemical Fixation of CO2 with Epoxides Catalyzed by Zinc Metalated Schiff Base Organic Polymer.

A facile metalation of Schiff base organic polymer, Te-TETA obtained from terephthalaldehyde and triethylenetetramine, with zinc to produce metalated organic polymer, Te-TETA-Zn has been reported here. Both Te-TETA and Te-TETA-Zn were analyzed by various analytical techniques viz. FT-IR, PXRD, FE-SEM, EDX, XPS, TGA and BET. Further, HR-TEM images of metalated organic polymer, Te-TETA-Zn was also recorded. EDX and XPS analyses clearly revealed the metalation of Zn in the organic polymer. Further, a huge transformation from the spherical morphology of Te-TETA to the flattened structure in Te-TETA-Zn can be seen in the FE-SEM and TEM images endorsing the successful coordination of zinc with the N-coordinating sites. An investigation of the catalytic activity of Te-TETA-Zn in combination with tetrabutylammonium bromide (TBAB, 2 mol%) reveals it to be an efficient heterogeneous catalyst component for the chemical fixation of CO2 to epoxides producing cyclic carbonate products (up to 99% conversion) under reaction conditions [Te-TETA-Zn (20 mg), TBAB (2 mol%), 5 bar CO2 pressure, 60 °C, 4 h]. [ABSTRACT FROM AUTHOR]