Two-photon photosensitized production of singlet oxygen: sensitizers with phenylene-ethynylene-based chromophores.
[reaction: see text] Singlet molecular oxygen (a(1)Delta(g)) has been produced and optically monitored in time-resolved experiments upon nonlinear two-photon excitation of photosensitizers that contain triple bonds as an integral part of the chromophore. Both experiments and ab initio computations indicate that the photophysical properties of alkyne-containing sensitizers are similar to those in the alkene-containing analogues. Most importantly, however, in comparison to the analogue that contains double bonds, the sensitizer containing alkyne moieties is more stable against singlet-oxygen-mediated photooxygenation reactions. This increased stability can be advantageous, particularly with respect to two-photon singlet oxygen imaging experiments in which data are collected over comparatively long time periods.
McIlroy
Sean P
SP
Department of Chemistry, University of Aarhus, DK-8000 Arhus, Denmark.
Cló
Emiliano
E
Nikolajsen
Lars
L
Frederiksen
Peter K
PK
Nielsen
Christian B
CB
Mikkelsen
Kurt V
KV
Gothelf
Kurt V
KV
Ogilby
Peter R
PR