title: pH-Switchable "Off-On-Off" Near-Infrared Luminescence Based on a Dinuclear Ruthenium(II) Complex.
abstract: The pH-switchable room-temperature near-infrared (NIR) phosphorescence emission based on ruthenium(II) polypyridyl complexes has been very rarely reported, even though it is very desirable for applications in sensing, switching, and logic molecular devices and bioimaging. Here we report a novel dinuclear ruthenium(II) complex in an aerated acetonitrile solution featuring a bright NIR emission centered at 760 nm with an absolute quantum yield of 1.03%, a large Stokes shift of 254 nm, and a long emission lifetime of 108.3 ± 0.4 ns. The complex in a Britton-Roberson buffer also exhibited pH-induced "off-on-off" NIR luminescent switches with a maximum intensity enhancement factor of 41 and one of the switching events occurring near the physiological pH range.
authors.affiliation: Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Meng
authors.affiliation: Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Ze-Bao
authors.initials: ZB
authors.lastname: Zheng
authors.affiliation: Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Ke-Zhi
authors.identifier: http://orcid.org/0000-0003-2642-1770
authors.initials: KZ
authors.lastname: Wang