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Title: Excited-state properties of ruthenium(II) tris chelate complexes containing the ligands 2,2'-bipyridine (bpy) and dipyrido(3,2-c:2',3'-e)pyridazine (taphen)

Abstract

The complexes Ru(bpy)/sub 3-n/(taphen)/sub n//sup 2 +/ (n = 0-3, bpy = 2,2'-bipyridine, taphen = dipyrido(3,2-c:2',3'-e)pyridazine) have been prepared, and their absorption spectra, emission spectra, emission lifetimes, luminescence quantum yields, and redox potentials have been measured. The first reduction potential of the three taphen-containing complexes is almost the same as (approx. -0.72 V vs. SCE) and much less negative than that of Ru(bpy)/sub 3//sup 2 +/ (-1.35 V). The first oxidation potential increases by 0.11 V as each bpy of Ru(bpy)/sub 3//sup 2 +/ is replaced by taphen. The maximum of the metal-to-ligand charge-transfer (MLCT) absorption band of the taphen-containing complexes lies at slightly higher energy than that of Ru(bpy)/sub 3//sup 2 +/, while the emission maximum lies at lower energy. The lifetime of the emitting excited state is in the 1-..mu..s range at 77 K and in the 0.1-..mu..s range at room temperature, as expected for formally triplet MLCT excited states. Ru(taphen/sub 3//sup 2 +/ does not follow the correlation observed by other RuL/sub 3//sup 2 +/ complexes between energy of the absorption maximum and (E/sub 1/2/(RuL/sub 3//sup 3+/2+/) - E/sub 1/2/(RuL/sub 3//sup 2+/+)), showing that different ..pi..*(taphen) orbitals are involved in the two processes. Examination of the analogousmore » correlation involving the emission maxima shows that the ..pi..*(taphen) orbital involved in reduction is presumably the same as that involved in the luminescence emission. 52 references, 4 figures, 2 tables.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Istituto Chimico G. Ciamician, Bologna, Italy
OSTI Identifier:
5889785
Resource Type:
Journal Article
Journal Name:
Inorg. Chem.; (United States)
Additional Journal Information:
Journal Volume: 25:3
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; BIPYRIDINES; CHEMICAL PREPARATION; LIFETIME; LUMINESCENCE; QUANTUM EFFICIENCY; REDOX POTENTIAL; PYRIDAZINES; RUTHENIUM COMPLEXES; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; CHELATES; ELECTRON TRANSFER; EMISSION SPECTRA; EMISSION SPECTROSCOPY; EXCITED STATES; EXPERIMENTAL DATA; LIGANDS; LOW TEMPERATURE; MEDIUM TEMPERATURE; AZINES; COMPLEXES; DATA; EFFICIENCY; ENERGY LEVELS; HETEROCYCLIC COMPOUNDS; INFORMATION; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PYRIDINES; SPECTRA; SPECTROSCOPY; SYNTHESIS; TRANSITION ELEMENT COMPLEXES; 400500* - Photochemistry; 360201 - Ceramics, Cermets, & Refractories- Preparation & Fabrication

Citation Formats

Jursi, A, Belser, P, Barigelletti, F, Von Zelewsky, A, and Balzani, V. Excited-state properties of ruthenium(II) tris chelate complexes containing the ligands 2,2'-bipyridine (bpy) and dipyrido(3,2-c:2',3'-e)pyridazine (taphen). United States: N. p., 1986. Web. doi:10.1021/ic00223a005.
Jursi, A, Belser, P, Barigelletti, F, Von Zelewsky, A, & Balzani, V. Excited-state properties of ruthenium(II) tris chelate complexes containing the ligands 2,2'-bipyridine (bpy) and dipyrido(3,2-c:2',3'-e)pyridazine (taphen). United States. https://doi.org/10.1021/ic00223a005
Jursi, A, Belser, P, Barigelletti, F, Von Zelewsky, A, and Balzani, V. Wed . "Excited-state properties of ruthenium(II) tris chelate complexes containing the ligands 2,2'-bipyridine (bpy) and dipyrido(3,2-c:2',3'-e)pyridazine (taphen)". United States. https://doi.org/10.1021/ic00223a005.
@article{osti_5889785,
title = {Excited-state properties of ruthenium(II) tris chelate complexes containing the ligands 2,2'-bipyridine (bpy) and dipyrido(3,2-c:2',3'-e)pyridazine (taphen)},
author = {Jursi, A and Belser, P and Barigelletti, F and Von Zelewsky, A and Balzani, V},
abstractNote = {The complexes Ru(bpy)/sub 3-n/(taphen)/sub n//sup 2 +/ (n = 0-3, bpy = 2,2'-bipyridine, taphen = dipyrido(3,2-c:2',3'-e)pyridazine) have been prepared, and their absorption spectra, emission spectra, emission lifetimes, luminescence quantum yields, and redox potentials have been measured. The first reduction potential of the three taphen-containing complexes is almost the same as (approx. -0.72 V vs. SCE) and much less negative than that of Ru(bpy)/sub 3//sup 2 +/ (-1.35 V). The first oxidation potential increases by 0.11 V as each bpy of Ru(bpy)/sub 3//sup 2 +/ is replaced by taphen. The maximum of the metal-to-ligand charge-transfer (MLCT) absorption band of the taphen-containing complexes lies at slightly higher energy than that of Ru(bpy)/sub 3//sup 2 +/, while the emission maximum lies at lower energy. The lifetime of the emitting excited state is in the 1-..mu..s range at 77 K and in the 0.1-..mu..s range at room temperature, as expected for formally triplet MLCT excited states. Ru(taphen/sub 3//sup 2 +/ does not follow the correlation observed by other RuL/sub 3//sup 2 +/ complexes between energy of the absorption maximum and (E/sub 1/2/(RuL/sub 3//sup 3+/2+/) - E/sub 1/2/(RuL/sub 3//sup 2+/+)), showing that different ..pi..*(taphen) orbitals are involved in the two processes. Examination of the analogous correlation involving the emission maxima shows that the ..pi..*(taphen) orbital involved in reduction is presumably the same as that involved in the luminescence emission. 52 references, 4 figures, 2 tables.},
doi = {10.1021/ic00223a005},
url = {https://www.osti.gov/biblio/5889785}, journal = {Inorg. Chem.; (United States)},
number = ,
volume = 25:3,
place = {United States},
year = {1986},
month = {1}
}