Host-Guest Complexes of C-Ethyl-2-methylresorcinarene and Aromatic N,N′-Dioxides

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2017
Major/Subject
Mcode
Degree programme
Language
en
Pages
417–423
Series
ChemistryOpen, Volume 6, issue 3
Abstract
The C-ethyl-2-methylresorcinarene (1) forms 1:1 in-cavity complexes with aromatic N,N′-dioxides, only if each of the aromatic rings has an N-O group. The structurally different C-shaped 2,2′-bipyridine N,N′-dioxide (2,2′-BiPyNO) and the linear rod-shaped 4,4′-bipyridine N,N′-dioxide (4,4′-BiPyNO) both form 1:1 in-cavity complexes with the host resorcinarene in C4v crown and C2v conformations, respectively. In the solid state, the host-guest interactions between the 1,3-bis(4-pyridyl)propane N,N′-dioxide (BiPyPNO) and the host 1 stabilize the unfavorable anti-gauche conformation. Contrary to the N,N′-dioxide guests, the mono-N-oxide guest, 4-phenylpyridine N-oxide (4PhPyNO), does not form an in-cavity complex in the solid state. The host-guest complexation and the relative guest affinities were studied through 1HNMR competition experiments in methanol. Single-crystal X-ray crystallography of the 1:1 complexes supports the proposed solution-state structures, also revealing strong hydrogen bonds between the hostand the guests, not observed in solution owing to hydrogen/deuterium (H/D) exchange processes in methanol.
Description
Keywords
Conformation, N,N′-dioxides, Resorcinarenes, Supramolecular chemistry, Weak interactions
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Citation
Puttreddy , R , Beyeh , N K , Ras , R H A & Rissanen , K 2017 , ' Host-Guest Complexes of C-Ethyl-2-methylresorcinarene and Aromatic N,N′-Dioxides ' , ChemistryOpen , vol. 6 , no. 3 , pp. 417–423 . https://doi.org/10.1002/open.201700026