Phasor Representation of Monomer-Excimer Kinetics: General Results and Application to Pyrene

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Martelo, L (Author) Other; Fedorov, A (Author) Other; Berberan Santos, MN (Author) Other

Journal

Title: Journal of Physical Chemistry B Materials

Vol. 119

ISSN: 1089-5647

Publisher: American Chemical Society

Indexing

Scopus - 6 Citations

Other information

Authenticus ID: P-00K-125

DOI: 10.1021/acs.jpcb.5b08875

Abstract (EN): Phasor plots of the fluorescence intensity decay (plots of the Fourier sine transform versus the Fourier cosine transform, for one or several angular frequencies) are being increasingly used in studies of homogeneous and heterogeneous systems. In this work, the phasor approach is applied to monomer-excimer kinetics. The results obtained allow a clear visualization of the information contained in the decays. The monomer phasor falls inside the universal circle, whereas the excimer phasor lies outside it, but within the double-exponential outer boundary curve. The monomer and excimer phasors, along with those corresponding to the two exponential components of the decays, fall on a common straight line and obey the generalized lever rule. The clockwise trajectories described by both phasors upon monomer concentration increase are identified. The phasor approach allows discussing in a single graphic not only the effect of concentration but also that of rate constants, including the evolution from irreversible kinetics to fast excited-state equilibrium upon a temperature increase. The obtained results are applied to the fluorescence decays of pyrene monomer and excimer in methylcyclohexane at room temperature. A straightforward method of monomer-excimer lifetime data analysis based on linear plots is also introduced. © 2015 American Chemical Society.

Language: English

Type (Professor's evaluation): Scientific