Photostable Fluorophenyl-Substituted Cyclometalated Platinum(II) Emitters for Monitoring of Molecular Oxygen in Real Time

The effects of fluorophenyl substituents
on the photoluminescence,
redox properties, and oxygen sensing behaviors of the cyclometalated
Pt­(II) complexes are reported. The Pt­(II) complexes with fluorophenyl
substituents at the para position on the phenyl ring
of 2-phenylpyridine (ppy) exhibit higher oxygen sensitivities than
those at the meta position. Photodegradation tests
demonstrate that the introduction of fluorophenyl substituents can
strongly improve the photostability of cyclometalated Pt­(II) complexes.
Fast response and recovery times of oxygen sensing films are obtained
in 3.0 s on going from 0% O2 to 100% O2 and
in 4.0 s on going from 100% O2 to 0% O2 (95%
recovery of the luminescence), respectively. The oxygen sensing films
show excellent operational stability in 4000 s saturation O2/N2 cycles, which meets the requirement of monitoring
molecular oxygen in real time.