Luminescent Pincer Platinum(II) Complexes with Emission Quantum Yields up to Almost Unity: Photophysics, Photoreductive C-C Bond Formation, and Materials Applications

摘要

Luminescent pincer-type Pt-II complexes supported by C-deprotonated pi-extended tridentate R-C boolean AND N boolean AND N R' ligands and pentafluorophenylacetylide ligands show emission quantum yields up to almost unity. Femtosecond time-resolved fluorescence measurements and time-dependent DFT calculations together reveal the dependence of excited-state structural distortions of Pt(R-C boolean AND N boolean AND N-R')(C C-C6F5) on the positional isomers of the tridentate ligand. Pt complexes Pt(R-C boolean AND N boolean AND N-R')(C C-Ar) are efficient photocatalysts for visible-light-induced reductive C-C bond formation. The Pt(R-C boolean AND N boolean AND N-R')(C C-C6F5) complexes perform strongly as phosphorescent dopants for green-and red-emitting organic light-emitting diodes (OLEDs) with external quantum efficiency values over 22.1. These complexes are also applied in two-photon cellular imaging when incorporated into mesoporous silica nanoparticles (MSNs).