Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2010-10-01

Journal: EUROPEAN JOURNAL OF INORGANIC CHEMISTRY

Included Journals: Scopus、SCIE

Issue: 28

Page Number: 4470-4482

ISSN: 1434-1948

Key Words: Sensors; Phosphorescence; Platinum; Fluorescence; Density functional calculations

Abstract: Pyrene-containing cyclometallated Pt(II) complexes, with the pyrene moiety directly cyclometallated (Pt-1) or connected to a 2-phenylpyridine (ppy) ligand through a C-C (Pt-2) or C  C bond (Pt-3), and a control complex with a phenyl group attached to the ppy ligand (Pt-4) have been prepared. Room-temperature deep-red/near-IR (NW) phosphorescence emission (650-800 nm) was observed for Pt-1, Pt-2 and Pt-3, whereas Pt-4 showed emission at 528 nm. We found that Pt-2, in which the pyrene moiety is not directly cyclometallated, shows intense pyrene-based phosphorescence, which contrasts with a previous report that direct cyclometallation is necessary for the observation of the phosphorescence of pyrene in cyclometallated complexes. Besides the phosphorescence emission in the deep-red/near-IR range, a fluorescence emission band at higher energy was observed. Thus, these complexes can be described as unichromophore multi-emissive materials. Normal (3)MLCT/(3)IL emission at 528 nm was observed for Pt-4. The UV/Vis absorption and phosphorescence emissions of the complexes were rationalized by DFT/TDDFT calculations. Theoretical calculations propose pyrene-localized T(1) states ((3)IL) for Pt-1, Pt-2 and Pt-3, which is supported by the experimental results. The complexes were used in luminescent O(2)-sensing experiments. These studies will be helpful in the development of room-temperature phosphorescent materials and their application as luminescent molecular sensing or electroluminescent materials are promising.