TY - JOUR
T1 - A Dynamic Tetracationic Macrocycle Exhibiting Photoswitchable Molecular Encapsulation
AU - Wu, Huang
AU - Chen, Yong
AU - Zhang, Long
AU - Anamimoghadam, Ommid
AU - Shen, Dengke
AU - Liu, Zhichang
AU - Cai, Kang
AU - Pezzato, Cristian
AU - Stern, Charlotte L.
AU - Liu, Yu
AU - Stoddart, J. Fraser
N1 - Funding Information:
This research was conducted as part of the Joint Center of Excellence in Integrated Nanosystems (JCIN) at King Abdulaziz City for Science and Technology (KACST) and Northwestern University (NU). The authors thank both KACST and NU for their continued support of this research. The authors thank the National Nature Science Foundation of China (NNSFC, Grant Nos. 21432004, 21672113, 21772099, 21861132001, and 91527301) for financial support. This work was also supported by the China Scholarship Council.
Funding Information:
This research was conducted as part of the Joint Center of Excellence in Integrated Nanosystems (JCIN) at King Abdulaziz City for Science and Technology (KACST) and Northwestern University (NU). The authors thank both KACST and NU for their continued support of this research. The authors thank the National Nature Science Foundation of China (NNSFC, Grant Nos. 21432004, 21672113, 21772099, 21861132001 and 91527301) for financial support. This work was also supported by the China Scholarship Council.
PY - 2019/1/23
Y1 - 2019/1/23
N2 - Designing macrocycles with appropriate molecular recognition features that allow for the integration of suitable external stimuli to control host-guest processes is a challenging endeavor which enables molecular containers to solubilize, stabilize, and separate chemical entities in an externally controllable manner. Herein, we introduce photo- and thermal-responsive elements into a semi-rigid tetracationic cyclophane, OPVEx 2 Box 4+ , that is composed of oligo(p-phenylenevinylene) pyridinium units and the biphenylene-bridged 4,4-bipyridinium extended viologens and adopts a rectangle-like geometry. It transpires that when the photoactive oligo(p-phenylenevinylene) pyridinium unit is incorporated in a macrocyclic scaffold, its reversibility is dramatically improved, and the configurations of the cyclophane can go back and forth between (EE)- and (EZ)-isomers upon alternating blue light irradiation and heating. When the macrocycle is found in its (EE)-configuration, it is capable of binding various π-electron-rich guests - e.g., anthracene and perylene - as well as π-electron-deficient guests - e.g., 9,10-anthraquinone and 5,12-tetracenequinone - through charge-transfer and van der Waals interactions. When irradiated with blue light, the (EE)-isomer of the cyclophane can be transformed successfully to the (EZ)-isomer, resulting in the switching off of the binding affinity for guest molecules, which are bound once again upon heating. The use of light and heat as external stimuli to control host-guest interactions involving a multi-responsive host and various guests provides us with a new opportunity to design and construct more-advanced molecular switches and machines.
AB - Designing macrocycles with appropriate molecular recognition features that allow for the integration of suitable external stimuli to control host-guest processes is a challenging endeavor which enables molecular containers to solubilize, stabilize, and separate chemical entities in an externally controllable manner. Herein, we introduce photo- and thermal-responsive elements into a semi-rigid tetracationic cyclophane, OPVEx 2 Box 4+ , that is composed of oligo(p-phenylenevinylene) pyridinium units and the biphenylene-bridged 4,4-bipyridinium extended viologens and adopts a rectangle-like geometry. It transpires that when the photoactive oligo(p-phenylenevinylene) pyridinium unit is incorporated in a macrocyclic scaffold, its reversibility is dramatically improved, and the configurations of the cyclophane can go back and forth between (EE)- and (EZ)-isomers upon alternating blue light irradiation and heating. When the macrocycle is found in its (EE)-configuration, it is capable of binding various π-electron-rich guests - e.g., anthracene and perylene - as well as π-electron-deficient guests - e.g., 9,10-anthraquinone and 5,12-tetracenequinone - through charge-transfer and van der Waals interactions. When irradiated with blue light, the (EE)-isomer of the cyclophane can be transformed successfully to the (EZ)-isomer, resulting in the switching off of the binding affinity for guest molecules, which are bound once again upon heating. The use of light and heat as external stimuli to control host-guest interactions involving a multi-responsive host and various guests provides us with a new opportunity to design and construct more-advanced molecular switches and machines.
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U2 - 10.1021/jacs.8b10526
DO - 10.1021/jacs.8b10526
M3 - Article
C2 - 30475608
AN - SCOPUS:85059690426
VL - 141
SP - 1280
EP - 1289
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 3
ER -