Atropisomerization of di-para-substituted propyl-bridged biphenyl cyclophanes

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.

Full text not available from this repository.

Official URL: http://edoc.unibas.ch/dok/A6083385

Downloads: Statistics Overview


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)
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
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:05 Apr 2017 10:13
Deposited On:24 May 2013 09:05

Repository Staff Only: item control page