Temperature Dependence of Primary and Secondary Fluorescence Quantum Yield Standards

Landgraf, S. (Speaker)

Activity: Talk or presentationPoster presentationScience to science

Description

Fluorescence quantum yields are still an increasing topic in photochemistry and photophysics. The number of articles in the literature is gradually increasing (approx. 5% per year). Most authors did not give precise experimental conditions when using relative fluorescence standards. Especially the temperature is not given or even not controlled. Inside a compact fluorescence spectrometer the temperature is far from constant and far from room temperature when no controlled cuvette holder is applied. However, this is not a standard equipment and has to be bought and installed separately.

For all commonly applied solvents, this error is presented in a range from 20 to 30 °C. As the temperatures of reference and sample are not necessarily the same, this error can duplicate in the worst case.

Secondly, all fluorescent molecules with a quantum yield less than 1 should be temperature dependent. The reason is the non-radiative decay, which is an activated process. In fact, the results are more complicated as there are positive and negative deviations from zero. Therefore, all primary and secondary standards recommend by the IUPAC [1] are investigated for their temperature dependence in a range of 20 to 30 °C. Again, this error can duplicate.

This presentation will show clearly that new fluorescence quantum yields without temperature control should not by published any more in international peer-reviewed journals.

Literature:
[1] A.M. Brouwer, Pure Appl. Chem., 2011, 83, 2213-2228. 10.1351/PAC-REP-10-09-3.

Period10 Sep 201812 Sep 2018
Event title26. Lecture Conference on Photochemistry
Event typeConference
LocationGarching, Germany
Degree of RecognitionInternational