Rotzler, Jurgen and Gsellinger, Heiko and Bihlmeier, Angela and Gantenbein, Markus and Vonlanthen, David and Haussinger, Daniel and Klopper, Wim and Mayor, Marcel. (2013) Atropisomerization of di-para-substituted propyl-bridged biphenyl cyclophanes. Organic and Biomolecular Chemistry, 11. pp. 110-118.
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Official URL: http://edoc.unibas.ch/dok/A6083385
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Abstract
The influence of electron donors and electron acceptors of variable strength in the 4 and 4' position of 2 and 2' propyl-bridged axial chiral biphenyl cyclophanes on their atropisomerization process was studied. Estimated free energies [capital Delta]G[double dagger](T) of the rotation around the central biphenyl bond which were obtained from 1H-NMR coalescence measurements were correlated to the Hammett parameters [sigma]p as a measure for electron donor and acceptor strength. It is demonstrated that the resulting nice linear correlation is mainly based on the influence of the different substituents on the [small pi]-system of the biphenyl cyclophanes. By lineshape analysis the rate constants were calculated and by the use of the Eyring equation the enthalpic and entropic contributions were evaluated. Density functional theory calculations show a planar transition state of the isomerization process and the calculated energy barriers based on this reaction mechanism are in good agreement with the experimentally obtained free energies.
Faculties and Departments: | 05 Faculty of Science > Departement Chemie > Chemie > Molecular Devices and Materials (Mayor) |
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UniBasel Contributors: | Mayor, Marcel and Rotzler, Jürgen and Gsellinger, Heiko and Gantenbein, Markus and Vonlanthen, David and Häussinger, Daniel |
Item Type: | Article, refereed |
Article Subtype: | Research Article |
Publisher: | Royal Society of Chemistry |
ISSN: | 1477-0520 |
e-ISSN: | 1477-0539 |
Note: | Publication type according to Uni Basel Research Database: Journal article |
Identification Number: |
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Last Modified: | 05 Apr 2017 10:13 |
Deposited On: | 24 May 2013 09:05 |
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