Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

The Role of Excited State Molecular Association in Photoreactions of Dibenzoylmethanatoboron Difluoride With Conjugated Enones and En-Esters: an Anomalous Excimer Reaction

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

This Article is currently unavailable for purchase.
Add to Favorites
You must be logged in to use this functionality

Cover image Placeholder

The singlet excited state of the title borofluoride, *DBMBF2, reacted efficiently with acyclic enones and en-esters but only feebly with the corresponding excimer in analogy to simple acyclic olefins to give cycloaddition products, in spite of substantially different electronic character of the double bonds. Cyclic enones, on the contrary, reacted with both *DBMBF2 and the excimer with increasing fluorescence quenching constants and adduct quantum yields as the rigidity of enone rings relaxes. They interacted with the excimer to cause the enone stimulated excimer dissociation which occurred most likely by the intermediary of the enone exciplexes. The interaction of 2-cyclopentenone (CP) by this process caused strong increases in *DBMBF2 fluorescence intensity, that was interpreted to arise from a fast reverse step (k-x) from the exciplex as shown by increasing *DBMBF2 fluorescence intensities upon addition of CP. Apparently the exciplexes from 2-cyclohexenone, 2-cyclooctenone and 2-cyclododecenone had a decreasing degree of reversibility (i.e., relatively smaller reverse reaction rates): this trend caused Φa increases and, correspondingly, lesser enhancement of *DBMBF2 fluorescence in the same order. The last enone, while mainly reacted with excimer, showed almost the same reactivity and Φa pattern of acyclic enones. In contrast to cyclic olefins, the last three enones reacted to show decreased Φa on increasing initial [DBMBF2] (i.e., higher excimer concentrations); an hidden deactivation step was implicated in the excimer reaction with these enones. The anomalous reaction patterns were assumed to be caused by differences in the geometrical orientation of an enone within exciplexes and of enone attack on the excimer.

Affiliations: 1: Department of chemistry, Simon Fraser University, Burnaby, British Columbia, CANADA V5A 1S6; 2: Department of Chemistry, Nankai University, Tianjin, 700031, PEOPLE'S REPUBLIC OF CHINA


Full text loading...


Data & Media loading...

Article metrics loading...



Can't access your account?
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation