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Infrared Study of Intercomponent Interactions in a Switchable Hydrogen‐Bonded Rotaxane
Author(s) -
Jagesar Dhiredj C.,
Hartl František,
Buma Wybren Jan,
Brouwer Albert M.
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701531
Subject(s) - hydrogen bond , chemistry , solvent , rotaxane , acceptor , amide , infrared spectroscopy , photochemistry , double bond , single bond , triple bond , hydrogen , solvent effects , crystallography , molecule , group (periodic table) , polymer chemistry , organic chemistry , supramolecular chemistry , crystal structure , physics , condensed matter physics
The macrocycle in rotaxane 1 is preferentially hydrogen bonded to the succinamide station in the neutral form, but can be moved to the naphthalimide station by one‐electron reduction of the latter. The hydrogen bonding between the amide NH groups of the macrocycle and the CO groups in the binding stations in the thread was studied with IR spectroscopy in different solvents in both states. In addition, the solvent effect on the vibrational frequencies was analyzed; a correlation with the solvent acceptor number (AN) was observed. The conformational switching upon reduction could be detected by monitoring the hydrogen‐bond‐induced shifts of the ν (CO) frequencies of the CO groups of the succinamide and the reduced naphthalimide stations. The macrocycle was found to shield the encapsulated station from the solvent: wavenumbers of ν (CO) bands of the CO groups residing inside the macrocycle cavity remain unaffected by the solvent polarity.