Jump to main content
Jump to site search


Activation volumes for cis-to-trans isomerisation reactions of azophenols. A clear mechanistic indicator?

Abstract

Abstract: The thermal cis-to-trans isomerisation reaction of a series of hydroxy-substituted azo derivatives were studied kinetico-mechanistically as a function of temperature and pressure in order to investigate the possible role of the solvent in controlling the isomerisation mechanism, viz. inversion versus rotation. The variation of the observed first order rate constants for kinetic runs carried out at different temperatures and pressures were used to determine the thermal activation parameters ∆H≠ and ∆S≠, and the pressure activation parameter ∆V≠. In addition, some experiments with deuterated species or solvents were also performed. The reported results could be interpreted as indicative of a changeover from an inversion mechanism for non-polar solvents to a rotation mechanism for polar solvents, capable of hydrogen bonding, for some of the systems studied. However, the operation of a rotation mechanism in all studied cases can account more consistently for the data observed.

Back to tab navigation

Supplementary files

Publication details

The article was received on 30 Oct 2017, accepted on 04 Dec 2017 and first published on 05 Dec 2017


Article type: Paper
DOI: 10.1039/C7CP07349F
Citation: Phys. Chem. Chem. Phys., 2017, Accepted Manuscript
  •   Request permissions

    Activation volumes for cis-to-trans isomerisation reactions of azophenols. A clear mechanistic indicator?

    D. Velasco Castrillo, J. Garcia-Amorós, M. Martinez, R. V. Eldik, G. Stochel and G. Stopa, Phys. Chem. Chem. Phys., 2017, Accepted Manuscript , DOI: 10.1039/C7CP07349F

Search articles by author

Spotlight

Advertisements