DC Field | Value | Language |
---|---|---|
dc.contributor.author | Zhu, Zhixue | ko |
dc.contributor.author | Fahrenbach, Albert C. | ko |
dc.contributor.author | Li, Hao | ko |
dc.contributor.author | Barnes, Jonathan C. | ko |
dc.contributor.author | Liu, Zhichang | ko |
dc.contributor.author | Dyar, Scott M. | ko |
dc.contributor.author | Zhang, Huacheng | ko |
dc.contributor.author | Lei, Juying | ko |
dc.contributor.author | Carmieli, Raanan | ko |
dc.contributor.author | Sarjeant, Amy A. | ko |
dc.contributor.author | Stern, Charlotte L. | ko |
dc.contributor.author | Wasielewski, Michael R. | ko |
dc.contributor.author | Stoddart, James Fraser | ko |
dc.date.accessioned | 2013-03-13T00:29:42Z | - |
dc.date.available | 2013-03-13T00:29:42Z | - |
dc.date.created | 2012-10-09 | - |
dc.date.created | 2012-10-09 | - |
dc.date.issued | 2012-07 | - |
dc.identifier.citation | JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, v.134, no.28, pp.11709 - 11720 | - |
dc.identifier.issn | 0002-7863 | - |
dc.identifier.uri | http://hdl.handle.net/10203/104006 | - |
dc.description.abstract | Two redox-active bistable [2]catenanes composed of macrocyclic polyethers of different sizes incorporating both electron-rich 1,5-dioxynaphthalene (DNP) and electron-deficient 4,4'-bipyridinium (BIPY2+) units, interlocked mechanically with the tetracationic cyclophane cyclobis(paraquat-p-phenylene) (CBPQT(4+)), were obtained by donor acceptor template-directed syntheses in a threading-followed-by-cyclization protocol employing Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloadditions in the final mechanical-bond forming steps. These bistable [2]catenanes exemplify a design strategy for achieving redox-active switching between two translational isomers, which are driven (i) by donor-acceptor interactions between the CBPQT(4+) ring and DNP, or (ii) radical-radical interactions between CBPQT(2)((center dot+)) and BIPY center dot+, respectively. The switching processes, as well as the nature of the donor-acceptor interactions in the ground states and i:he radical-radical interactions in the reduced states, were investigated by single-crystal X-ray crystallography, dynamic H-1 NMR spectroscopy, cyclic voltammetry, UV/vis spectroelectrochemistry, and electron paramagnetic resonance (EPR) spectroscopy. The crystal structure of one of the [2]catenanes in its trisradical tricationic redox state provides direct evidence for the radical radical interactions which drive the switching processes for these types of mechanically interlocked molecules (MIMs). Variable-temperature H-1 NMR spectroscopy reveals a degenerate rotational motion of the BIPY2+ units in the CBPQT(4+) ring for both of the two [2]catenanes, that is governed by a free energy barrier of 14.4 kcal mol(-1) for the larger catenane and 17.0 kcal mol(-1) for the smaller one. Cyclic voltammetry provides evidence for the reversibility of the switching processes which occurs following a three-electron reduction of the three BIPY2+ units to their radical cationic forms. UV/vis spectroscopy confirms that the processes driving the switching are (i) of the donor-acceptor type, by the observation of a 530 nm charge-transfer band in the ground state, and (ii) of the radical-radical ilk in the switched state as indicated by an intense visible absorption (ca. 530 nm) and near-infrared (ca. 1100 nm) bands. EPR spectroscopic data reveal that, in the switched state, the interacting BIPY center dot+ radical cations are in a fast exchange regime. In general, the findings lay the foundations for future investigations where this radical-radical recognition motif is harnessed in bistable redox-active MIMs in order to achieve close to homogeneous populations of co-conformations in both the ground and switched states. | - |
dc.language | English | - |
dc.publisher | AMER CHEMICAL SOC | - |
dc.subject | TEMPLATE-DIRECTED SYNTHESIS | - |
dc.subject | PHOTOACTIVE MOLECULAR TRIAD | - |
dc.subject | INTERLOCKED MOLECULES | - |
dc.subject | SUPRAMOLECULAR CHEMISTRY | - |
dc.subject | INCLUSION COMPLEXES | - |
dc.subject | TERMINAL ALKYNES | - |
dc.subject | CLICK CHEMISTRY | - |
dc.subject | BORROMEAN RINGS | - |
dc.subject | CATENANES | - |
dc.subject | RECOGNITION | - |
dc.title | Controlling Switching in Bistable [2]Catenanes by Combining Donor-Acceptor and Radical-Radical Interactions | - |
dc.type | Article | - |
dc.identifier.wosid | 000306457900062 | - |
dc.identifier.scopusid | 2-s2.0-84863946995 | - |
dc.type.rims | ART | - |
dc.citation.volume | 134 | - |
dc.citation.issue | 28 | - |
dc.citation.beginningpage | 11709 | - |
dc.citation.endingpage | 11720 | - |
dc.citation.publicationname | JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | - |
dc.contributor.nonIdAuthor | Zhu, Zhixue | - |
dc.contributor.nonIdAuthor | Fahrenbach, Albert C. | - |
dc.contributor.nonIdAuthor | Li, Hao | - |
dc.contributor.nonIdAuthor | Barnes, Jonathan C. | - |
dc.contributor.nonIdAuthor | Liu, Zhichang | - |
dc.contributor.nonIdAuthor | Dyar, Scott M. | - |
dc.contributor.nonIdAuthor | Zhang, Huacheng | - |
dc.contributor.nonIdAuthor | Lei, Juying | - |
dc.contributor.nonIdAuthor | Carmieli, Raanan | - |
dc.contributor.nonIdAuthor | Sarjeant, Amy A. | - |
dc.contributor.nonIdAuthor | Stern, Charlotte L. | - |
dc.contributor.nonIdAuthor | Wasielewski, Michael R. | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordPlus | TEMPLATE-DIRECTED SYNTHESIS | - |
dc.subject.keywordPlus | PHOTOACTIVE MOLECULAR TRIAD | - |
dc.subject.keywordPlus | INTERLOCKED MOLECULES | - |
dc.subject.keywordPlus | SUPRAMOLECULAR CHEMISTRY | - |
dc.subject.keywordPlus | INCLUSION COMPLEXES | - |
dc.subject.keywordPlus | TERMINAL ALKYNES | - |
dc.subject.keywordPlus | CLICK CHEMISTRY | - |
dc.subject.keywordPlus | BORROMEAN RINGS | - |
dc.subject.keywordPlus | CATENANES | - |
dc.subject.keywordPlus | RECOGNITION | - |
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