TY - JOUR
T1 - Redox-Responsive Covalent Organic Nanosheets from Viologens and Calix[4]arene for Iodine and Toxic Dye Capture
AU - Skorjanc, Tina
AU - Shetty, Dinesh
AU - Sharma, Sudhir Kumar
AU - Raya, Jesus
AU - Traboulsi, Hassan
AU - Han, Dong Suk
AU - Lalla, Jayesh
AU - Newlon, Ryan
AU - Jagannathan, Ramesh
AU - Kirmizialtin, Serdal
AU - Olsen, John Carl
AU - Trabolsi, Ali
N1 - © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2018/6/18
Y1 - 2018/6/18
N2 - 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 6.00nm and 8.00nm, 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 angstrom in COP1(++) and 5.65 angstrom 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 degrees 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 15minutes at acidic pH.
AB - 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 6.00nm and 8.00nm, 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 angstrom in COP1(++) and 5.65 angstrom 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 degrees 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 15minutes at acidic pH.
KW - Congo red
KW - calix[4]arenes
KW - iodine capture
KW - nanosheets
KW - viologen
UR - http://www.scopus.com/inward/record.url?scp=85048777738&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048777738&partnerID=8YFLogxK
UR - http://www.mendeley.com/research/redoxresponsive-covalent-organic-nanosheets-viologens-calix4arene-iodine-toxic-dye-capture
U2 - 10.1002/chem.201800623
DO - 10.1002/chem.201800623
M3 - Article
C2 - 29665187
AN - SCOPUS:85048777738
SN - 0947-6539
VL - 24
SP - 8648
EP - 8655
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 34
ER -