Issue 33, 2009

Two-photon excited fluorescence depolarisation and electronic energy migration within donor–donor pairs

Abstract

A unified theoretical description is presented for one- and two-photon excited fluorescence depolarisation and electronic energy migration within pairs of chromophores. Two weakly coupled donor groups are linked via a rigid macromolecule with the ability to undergo restricted reorienting motions. Describing these reorienting motions as well as their influence on the coupling is rather complex, but can be accounted for by using the extended Förster theory. Here explicit expressions have been derived for chromophores belonging to the point groups D2h, D2 and C2v when residing in uniaxial potentials (i.e. C∞v symmetry). From the given basic equations, it is possible however, to derive the relevant equations for molecules of arbitrary symmetry in any uniaxial orienting potential. The expected time-resolved fluorescence anisotropy for different two-photon absorption tensors are compared for reorienting fluorophores in liquids, as well as in anisotropic systems. Simulated fluorescence depolarisation data are also displayed that mimic energy migration within pairs of two-photon excited donor molecules, which simultaneously undergo reorienting motions within effectively isotropic and uniaxially anisotropic environments. The obtained results demonstrate that the time-resolved fluorescence anisotropy strongly depends on the properties of the two-photon absorption tensor, as well as on using a linear or a circular polarisation of the excitation field.

Graphical abstract: Two-photon excited fluorescence depolarisation and electronic energy migration within donor–donor pairs

Article information

Article type
Paper
Submitted
12 Jan 2009
Accepted
12 May 2009
First published
12 Jun 2009

Phys. Chem. Chem. Phys., 2009,11, 7152-7160

Two-photon excited fluorescence depolarisation and electronic energy migration within donor–donor pairs

O. Opanasyuk, L. Ryderfors, E. Mukhtar and L. B.-Å. Johansson, Phys. Chem. Chem. Phys., 2009, 11, 7152 DOI: 10.1039/B900650H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements