Open AccessReversible Mechanical Switching of Magnetic Interactions in a Molecular Shuttle
Author(s) -
Bleve Valentina,
Schäfer Christian,
Franchi Paola,
Silvi Serena,
Mezzina Elisabetta,
Credi Alberto,
Lucarini Marco
Publication year - 2015
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201402142
Subject(s) - electron paramagnetic resonance , rotaxane , nitroxide mediated radical polymerization , dumbbell , chemistry , deprotonation , radical , molecular switch , crystallography , stereochemistry , nuclear magnetic resonance , molecule , polymer , physics , organic chemistry , supramolecular chemistry , crystal structure , polymerization , radical polymerization , medicine , ion , physical therapy
Invited for this months cover are the groups of Professors Marco Lucarini and Alberto Credi at the University of Bologna. The cover picture shows coupled and uncoupled states of a [2]rotaxane incorporating stable nitroxide radical units in both the ring and dumbbell components. Interaction between nitroxide radicals could be switched between noncoupled (three‐line electron paramagnetic resonance (EPR) spectrum) and coupled (five‐line EPR spectrum) upon deprotonation of the rotaxane NH 2 + centers that effects a quantitative displacement of a dibenzocrown macroring to a 4,4’‐bipyridinium recognition site. The complete base‐ and acid‐induced switching cycle of the EPR pattern was repeated several times without an appreciable loss of signal, highlighting the reversibility of the process. Hence, this molecular machine is capable of switching on/off magnetic interactions by chemically driven reversible mechanical effects. For more details, see the Communication on p. 18 ff.