TY - JOUR
T1 - Azobenzene-Equipped Covalent Organic Framework
T2 - Light-Operated Reservoir
AU - Das, Gobinda
AU - Prakasam, Thirumurugan
AU - Addicoat, Matthew A.
AU - Sharma, Sudhir Kumar
AU - Ravaux, Florent
AU - Mathew, Renny
AU - Baias, Maria
AU - Jagannathan, Ramesh
AU - Olson, Mark A.
AU - Trabolsi, Ali
N1 - Funding Information:
The research described here was sponsored by New York University Abu Dhabi (NYUAD), UAE. G.D., T.P., S.S., R.J., and A.T. thank NYUAD for its generous support of the research program at NYUAD. The research was carried out by using the Core Technology Platform resources at NYUAD. M.A.A. thanks the UK Materials Chemistry Consortium for HPC time on Thomas (EP/P020194).
Funding Information:
The research described here was sponsored by New York University Abu Dhabi (NYUAD), UAE. G.D., T.P., S.S., R.J., and A.T. thank NYUAD for its generous support of the research program at NYUAD. The research was carried out by using the Core Technology Platform resources at NYUAD. M.A.A. thanks the UK Materials Chemistry Consortium for HPC time on Thomas (EP/P020194).
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/12/4
Y1 - 2019/12/4
N2 - Light-operated materials have gained significant attention for their potential technological importance. To achieve molecular motion within extended networks, stimuli-responsive units require free space. The majority of the so far reported 2D-extended organic networks with responsive moieties restrict their freedom of motion on account of their connectivity providing constrained free volume for efficient molecular motion. We report here a light-responsive azobenzene-functionalized covalent organic framework (TTA-AzoDFP) designed in a way that the pendent azobenzene groups are pointing toward the pore channels with sufficient free volume necessary for the unencumbered dynamic motion to occur inside the pores of the covalent organic framework (COF) and undergo a reversible trans-cis photoisomerization upon light irradiation. The resulting hydrophobic COF was used for the storage of rhodamine B and its controlled release in solution by the mechanical motion of the azobenzene units triggered by ultraviolet-light irradiation. The TTA-AzoDFP displayed unprecedented photoregulated fluorescence emission behavior upon UV-light irradiation. Size, emission, and degree of hydrophobicity with respect to trans-cis-trans photoisomerization could be reversibly controlled by alternating UV- and visible-light exposure. The results reported here demonstrate once again the importance of the careful design of the linkers not only to allow the incorporation of molecular switches within the chemical structure of COFs but also to provide the required free space for not hindering their motion. The results demonstrate that responsive COFs could be suitable platforms for delivery systems that can be controlled by external stimuli.
AB - Light-operated materials have gained significant attention for their potential technological importance. To achieve molecular motion within extended networks, stimuli-responsive units require free space. The majority of the so far reported 2D-extended organic networks with responsive moieties restrict their freedom of motion on account of their connectivity providing constrained free volume for efficient molecular motion. We report here a light-responsive azobenzene-functionalized covalent organic framework (TTA-AzoDFP) designed in a way that the pendent azobenzene groups are pointing toward the pore channels with sufficient free volume necessary for the unencumbered dynamic motion to occur inside the pores of the covalent organic framework (COF) and undergo a reversible trans-cis photoisomerization upon light irradiation. The resulting hydrophobic COF was used for the storage of rhodamine B and its controlled release in solution by the mechanical motion of the azobenzene units triggered by ultraviolet-light irradiation. The TTA-AzoDFP displayed unprecedented photoregulated fluorescence emission behavior upon UV-light irradiation. Size, emission, and degree of hydrophobicity with respect to trans-cis-trans photoisomerization could be reversibly controlled by alternating UV- and visible-light exposure. The results reported here demonstrate once again the importance of the careful design of the linkers not only to allow the incorporation of molecular switches within the chemical structure of COFs but also to provide the required free space for not hindering their motion. The results demonstrate that responsive COFs could be suitable platforms for delivery systems that can be controlled by external stimuli.
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U2 - 10.1021/jacs.9b09643
DO - 10.1021/jacs.9b09643
M3 - Article
C2 - 31656067
AN - SCOPUS:85075457931
SN - 0002-7863
VL - 141
SP - 19078
EP - 19087
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 48
ER -