title: Two-photon photosensitized production of singlet oxygen: sensitizers with phenylene-ethynylene-based chromophores.
abstract: [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.
authors.affiliation: Department of Chemistry, University of Aarhus, DK-8000 Arhus, Denmark.
authors.forename: Sean P
authors.initials: SP
authors.lastname: McIlroy
authors.forename: Emiliano
authors.initials: E
authors.lastname: Cló
authors.forename: Lars
authors.initials: L
authors.lastname: Nikolajsen
authors.forename: Peter K
authors.initials: PK
authors.lastname: Frederiksen
authors.forename: Christian B
authors.initials: CB
authors.lastname: Nielsen
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Mikkelsen
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Gothelf
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ogilby