TY - JOUR
T1 - Electrostatically Driven Guest Binding in a Self-Assembled Porous Network at the Liquid/Solid Interface
AU - Iritani, Kohei
AU - Ikeda, Motoki
AU - Yang, Anna
AU - Tahara, Kazukuni
AU - Anzai, Masaru
AU - Hirose, Keiji
AU - De Feyter, Steven
AU - Moore, Jeffrey S.
AU - Tobe, Yoshito
N1 - Funding Information:
This work is supported by JSPS KAKENHI grant numbers 2435004 and 15H02164 and by the National Science Foundation CHE under grant number 16-10328. The authors would like to thank the School of Chemical Sciences NMR Lab and Mass Spectrometry Lab at University of Illinois at Urbana Champaign. S.D.F. thanks KU Leuveninternal funds and FWO.
Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2018/5/29
Y1 - 2018/5/29
N2 - We present here the construction of a self-assembled two-dimensional (2D) porous monolayer bearing a highly polar 2D space to study guest co-adsorption through electrostatic interactions at the liquid/solid interface. For this purpose, a dehydrobenzo[12]annulene (DBA) derivative, DBA-TeEG, having tetraethylene glycol (TeEG) groups at the end of the three alternating alkoxy chains connected by p-phenylene linkers was synthesized. As a reference host molecule, DBA-C10, having nonpolar C10 alkyl chains at three alternating terminals, was employed. As guest molecules, hexagonal phenylene-ethynylene macrocycles (PEMs) attached by triethylene glycol (TEG) ester and hexyl ester groups, PEM-TEG and PEM-C6, respectively, at each vertex of the macrocyclic periphery were used. Scanning tunneling microscopy observations at the 1,2,4-trichlorobenzene/highly oriented pyrolytic graphite interface revealed that PEM-TEG was immobilized in the pores formed by DBA-TeEG at higher probability because of electrostatic interactions such as dipole-dipole and hydrogen bonding interactions between oligoether units of the host and guest, in comparison to PEM-C6 with nonpolar groups. These observations are discussed based on molecular mechanics simulations to investigate the role of the polar functional groups. When a nonpolar host matrix formed by DBA-C10 was used, however, only phase separation and preferential adsorption were observed; virtually no host-guest complexation was discernible. This is ascribed to the strong affinity between the guest molecules which form by themselves densely packed van der Waals networks on the surface.
AB - We present here the construction of a self-assembled two-dimensional (2D) porous monolayer bearing a highly polar 2D space to study guest co-adsorption through electrostatic interactions at the liquid/solid interface. For this purpose, a dehydrobenzo[12]annulene (DBA) derivative, DBA-TeEG, having tetraethylene glycol (TeEG) groups at the end of the three alternating alkoxy chains connected by p-phenylene linkers was synthesized. As a reference host molecule, DBA-C10, having nonpolar C10 alkyl chains at three alternating terminals, was employed. As guest molecules, hexagonal phenylene-ethynylene macrocycles (PEMs) attached by triethylene glycol (TEG) ester and hexyl ester groups, PEM-TEG and PEM-C6, respectively, at each vertex of the macrocyclic periphery were used. Scanning tunneling microscopy observations at the 1,2,4-trichlorobenzene/highly oriented pyrolytic graphite interface revealed that PEM-TEG was immobilized in the pores formed by DBA-TeEG at higher probability because of electrostatic interactions such as dipole-dipole and hydrogen bonding interactions between oligoether units of the host and guest, in comparison to PEM-C6 with nonpolar groups. These observations are discussed based on molecular mechanics simulations to investigate the role of the polar functional groups. When a nonpolar host matrix formed by DBA-C10 was used, however, only phase separation and preferential adsorption were observed; virtually no host-guest complexation was discernible. This is ascribed to the strong affinity between the guest molecules which form by themselves densely packed van der Waals networks on the surface.
UR - http://www.scopus.com/inward/record.url?scp=85046655070&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85046655070&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.8b00699
DO - 10.1021/acs.langmuir.8b00699
M3 - Article
C2 - 29717878
AN - SCOPUS:85046655070
SN - 0743-7463
VL - 34
SP - 6036
EP - 6045
JO - Langmuir
JF - Langmuir
IS - 21
ER -