Selective Positioning of CB 8 on Two Linked Viologens and Electrochemically Driven Movement of the Host Molecule
2009 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 8, 1163-1172 p.Article in journal (Refereed) Published
The binding interactions between cucurbituril (CB) and a dicationic guest N,N-dimethyl-3,3'-dimethyl-4,4'-bipyridinium (DMV2+) have been investigated by various experimental techniques including NMR, ESI-MS, and UV/Vis and fluorescence spectroscopy. In a three-component system consisting of CB[81, N,N-dimethyl-4,4'-bipyridinium (MV2+) and DMV2+, CB was found to exhibit a higher binding affinity to DMV2+ than to MV2+, When DMV2+ was connected to MV2+ by an alkyl chain, the first equiv. of CB could be selectively positioned on the DMV2+ moiety, and then a second equiv. of CB was positioned on the MV2+ moiety. Spectroelectrochemical studies showed that upon the reduction of this system at -0.6 V vs. AgCl, the CB could move from the DMV2+ moiety to the MV+center dot radical, which formed a dimer inside the CB cavity. Molecular oxygen quenched the dimer, and the CB moved back to the DMV2+ moiety, indicating it molecular movement driven by electrochemistry. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Place, publisher, year, edition, pages
2009. no 8, 1163-1172 p.
IdentifiersURN: urn:nbn:se:kth:diva-18254DOI: 10.1002/ejoc.200801012ISI: 000264308100009ScopusID: 2-s2.0-62249117106OAI: oai:DiVA.org:kth-18254DiVA: diva2:336300
QC 201005252010-08-052010-08-052010-12-13Bibliographically approved