Redox-Responsive Covalent Organic Nanosheets from Viologens and Calix[4]arene for Iodine and Toxic Dye Capture.

Autor: Skorjanc T; Science Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates., Shetty D; Science Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates., Sharma SK; Engineering Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates., Raya J; CNRS/, Université de Strasbourg, 1, Rue Blaise Pascal, Strasbourg, 67000, France., Traboulsi H; King Faisal University-Ahsaa, Department of Chemistry, 31982, Ahsaa, Kingdom of Saudi Arabia., Han DS; Chemical Engineering Program, Texas A&M University at Qatar, Education City, Doha, Qatar., Lalla J; School of Sciences, Indiana University Kokomo, 2300 S. Washington Street, Kokomo, IN, 46902, USA., Newlon R; School of Sciences, Indiana University Kokomo, 2300 S. Washington Street, Kokomo, IN, 46902, USA., Jagannathan R; Engineering Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates., Kirmizialtin S; Science Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates., Olsen JC; School of Sciences, Indiana University Kokomo, 2300 S. Washington Street, Kokomo, IN, 46902, USA., Trabolsi A; Science Division, New York University Abu Dhabi, Experimental Research Building (C1, Saadiyat Island, United Arab Emirates.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Jun 18; Vol. 24 (34), pp. 8648-8655. Date of Electronic Publication: 2018 May 22.
DOI: 10.1002/chem.201800623
Abstrakt: Owing to their chemical and thermal stabilities, high uptake capacities, and easy recyclability, covalent organic polymers (COPs) have shown promise as pollutant sponges. Herein, we describe the use of diazo coupling to synthesize two cationic COPs, COP1 ++ and COP2 ++ , that incorporate a viologen-based molecular switch and an organic macrocycle, calix[4]arene. The COPs form nanosheets that have height profiles of 6.00 nm and 8.00 nm, respectively, based on AFM measurements. The sheets remain morphologically intact upon one- or two-electron reductions of their viologen subunits. MD simulations of the COPs containing dicationic viologens indicate that the calix[4]arenes adopt a partial cone conformation and that, in height, the individual 2D polymer layers are 5.48 Å in COP1 ++ and 5.65 Å in COP2 ++ , which, together with the AFM measurements, suggests that the nanosheets are composed of 11 and 14 layers, respectively. Whether their viologens are in dicationic, radical cationic, or neutral form, the COPs exhibit high affinity for iodine, reaching up to 200 % mass increase when exposed to iodine vapor at 70 °C, which makes the materials among the best-performing nanosheets for iodine capture reported in the literature. In addition, the COPs effectively remove Congo red from solution in the pH range of 2-10, reaching nearly 100 % removal within 15 minutes at acidic pH.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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