TY - JOUR
T1 - Catenation through a Combination of Radical Templation and Ring-Closing Metathesis
AU - Gibbs-Hall, Ian C.
AU - Vermeulen, Nicolaas A.
AU - Dale, Edward J.
AU - Henkelis, James J.
AU - Blackburn, Anthea K.
AU - Barnes, Jonathan C.
AU - Stoddart, J. Fraser
N1 - Funding Information:
This research is part of the Joint Center of Excellence in Integrated Nano-Systems (JCIN) at the King Abdulaziz City of Science and Technology (KACST) and Northwestern University (NU). The authors thank KACST and NU for their continued support of this research. I.C.G.-H. thanks the National Defense Science and Engineering Graduate Fellowship (FA9550-11-C-0028) from the U.S. Department of Defense. E.J.D. acknowledges the award of a Graduate Research Fellowship from the National Science Foundation (NSF) and a Ryan Fellowship from the NU International Institute for Nanotechnology (IIN). A.K.B. thanks Fulbright New Zealand for a Fulbright Graduate Award and the New Zealand Federation of Graduate Women for a Postgraduate Fellowship Award.
Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/12/23
Y1 - 2015/12/23
N2 - Synthesis of an electrochemically addressable [2]catenane has been achieved following formation by templation of a [2]pseudorotaxane employing radically enhanced molecular recognition between the bisradical dication obtained on reduction of the tetracationic cyclophane, cyclobis(paraquat-p-phenylene), and the radical cation generated on reduction of a viologen disubstituted with p-xylylene units, both carrying tetraethylene glycol chains terminated by allyl groups. This inclusion complex was subjected to olefin ring-closing metathesis, which was observed to proceed under reduced conditions, to mechanically interlock the two components. Upon oxidation, Coulombic repulsion between the positively charged and mechanically interlocked components results in the adoption of a co-conformation where the newly formed alkene resides inside the cavity of the tetracationic cyclophane. 1H NMR spectroscopic analysis of this hexacationic [2]catenane shows a dramatic upfield shift of the resonances associated with the olefinic and allylic protons as a result of them residing inside the tetracationic component. Further analysis shows high diastereoselectivity during catenation, as only a single (Z)-isomer is formed.
AB - Synthesis of an electrochemically addressable [2]catenane has been achieved following formation by templation of a [2]pseudorotaxane employing radically enhanced molecular recognition between the bisradical dication obtained on reduction of the tetracationic cyclophane, cyclobis(paraquat-p-phenylene), and the radical cation generated on reduction of a viologen disubstituted with p-xylylene units, both carrying tetraethylene glycol chains terminated by allyl groups. This inclusion complex was subjected to olefin ring-closing metathesis, which was observed to proceed under reduced conditions, to mechanically interlock the two components. Upon oxidation, Coulombic repulsion between the positively charged and mechanically interlocked components results in the adoption of a co-conformation where the newly formed alkene resides inside the cavity of the tetracationic cyclophane. 1H NMR spectroscopic analysis of this hexacationic [2]catenane shows a dramatic upfield shift of the resonances associated with the olefinic and allylic protons as a result of them residing inside the tetracationic component. Further analysis shows high diastereoselectivity during catenation, as only a single (Z)-isomer is formed.
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U2 - 10.1021/jacs.5b10623
DO - 10.1021/jacs.5b10623
M3 - Article
C2 - 26654320
AN - SCOPUS:84952837749
SN - 0002-7863
VL - 137
SP - 15640
EP - 15643
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 50
ER -