Excited State Dynamics of Bistridentate and Trisbidentate RuII Complexes of Quinoline-Pyrazole Ligands
Artikel i vetenskaplig tidskrift, 2019

Three homoleptic ruthenium(II) complexes, [Ru(Q3PzH)3]2+, [Ru(Q1Pz)3]2+, and [Ru(DQPz)2]2+, based on the quinoline-pyrazole ligands, Q3PzH (8-(3-pyrazole)-quinoline), Q1Pz (8-(1-pyrazole)-quinoline), and DQPz (bis(quinolinyl)-1,3-pyrazole), have been spectroscopically and theoretically investigated. Spectral component analysis, transient absorption spectroscopy, density functional theory calculations, and ligand exchange reactions with different chlorination agents reveal that the excited state dynamics for Ru(II) complexes with these biheteroaromatic ligands differ significantly from that of traditional polypyridyl complexes. Despite the high energy and low reorganization energy of the excited state, nonradiative decay dominates even at liquid nitrogen temperatures, where triplet metal-to-ligand-charge-transfer emission quantum yields range from 0.7 to 3.8%, and microsecond excited state lifetimes are observed. In contrast to traditional polypyridyl complexes where ligand exchange is facilitated by expansion of the metal-ligand bonds to stabilize a metal-centered state, photoinduced ligand exchange occurs in the bidentate complexes despite no substantial MC state population, while the tridentate complex is extremely photostable despite an activated decay route, highlighting the versatile photochemistry of nonpolypyridine ligands. © 2019 American Chemical Society.

Författare

L. A. Fredin

Lunds universitet

Lehigh University

Joachim Wallenstein

Chalmers, Fysik, Kondenserade materiens fysik

Elin Sundin

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Fysikalisk kemi

M. Jarenmark

Lunds universitet

Deise Fernanda Barbosa de Mattos

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Fysikalisk kemi

P. Persson

Lunds universitet

Maria Abrahamsson

Chalmers, Kemi och kemiteknik, Kemi och biokemi

Inorganic Chemistry

0020-1669 (ISSN) 1520-510X (eISSN)

Vol. In Press

Ämneskategorier

Oorganisk kemi

Atom- och molekylfysik och optik

Teoretisk kemi

DOI

10.1021/acs.inorgchem.9b01543

Mer information

Senast uppdaterat

2019-12-23