A new triptycene-derived macrotricyclic host containing two dibenzo-[18]-crown-6 moieties was synthesized and shown to form 1:1 complexes with paraquat derivatives in solution, in which the guests all thread the central cavity of the host. However, it was interestingly found that, depending on the paraquat derivatives with different functional groups, the host can form stable 1:1 or 1:2 complexes in different complexation modes in the solid state, which is significantly different from those of the macrotricyclic host containing two dibenzo-[24]-crown-8 moieties. The formation of the complexes was also proved by the ESI MS and electrochemical experiments. Moreover, it was found that the binding and release of the guests in the complexes could be easily controlled by the addition and removal of lithium ions.
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http://dx.doi.org/10.1021/jo3000755 | DOI Listing |
Chem Commun (Camb)
January 2016
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
A new acid/base controllable host-guest system based on a triptycene-derived macrotricyclic host and protonated 4,4'-bipyridinium/pyridinium salts was developed. Moreover, the competition complexation process between the host and two different kinds of 4,4'-bipyridinium salts could also be chemically controlled by acid and base.
View Article and Find Full Text PDFOrg Biomol Chem
February 2015
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
A novel water-soluble cylindrical macrotricyclic host containing one central cavity and two dibenzo-24-crown-8 lateral cavities was synthesized. It could form 1 : 2 complexes with N-methylquinolinium salts or N-methylisoquinolinium salts in water solution and in the solid state, in which multiple hydrogen-bonding and π-π stacking interactions between the host and the guests played an important role. Moreover, the complexation and decomplexation of the complexes between the host and the guests could be achieved by changing the pH of the solution, and the process could also be observed by the naked eye.
View Article and Find Full Text PDFAcc Chem Res
July 2014
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
CONSPECTUS: Synthetic macrocyclic hosts have played key roles in the development of host-guest chemistry. Crown ethers are a class of macrocyclic molecules with unique flexible structures. They have served as the first generation of synthetic hosts, and researchers have extensively studied them in molecular recognition.
View Article and Find Full Text PDFOrg Biomol Chem
May 2014
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Triptycene-derived macrotricyclic polyether containing an anthracene unit is a powerful host for 1,2-bis(pyridium)ethane, diquat and 2,7-diazapyrenium salt with association constants of the 1 : 1 complexes at >10(5) M(-1). Crystal structures showed that π-π stacking interactions between the host and the guests play an important role in the formation of the stable complexes.
View Article and Find Full Text PDFJ Org Chem
April 2013
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Complexation between a triptycene-derived macrotricyclic polyether containing two dibenzo-[30]-crown-10 cavities and different functionalized paraquat derivatives, diquat, and a 2,7-diazapyrenium salt in both solution and solid state was investigated in detail. It was found that depending on the guests with different terminal functional groups and structures, the macrotricyclic polyether could form 1:1 or 1:2 complexes with the guests in different complexation modes in solution and also in the solid state. Especially, the conformation of the macrotricyclic polyether was efficiently adjusted by the encapsulated guests, which was to some extent similar to substrate-induced fit of enzymes.
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