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.