title: N-heterocyclic donor- and acceptor-type ligands based on 2-(1H-[1,2,3]triazol-4-yl)pyridines and their ruthenium(II) complexes.
abstract: New 2-(1H-[1,2,3]triazol-4-yl)pyridine bidentate ligands were synthesized as bipyridine analogs, whereas different phenylacetylene moieties of donor and acceptor nature were attached at the 5-position of the pyridine unit. The latter moieties featured a crucial influence on the electronic properties of those ligands. The N-heterocyclic ligands were coordinated to ruthenium(II) metal ions by using a bis(4,4'-dimethyl-2,2'-bipyridine)ruthenium(II) precursor. The donor or acceptor capability of the 2-(1H-[1,2,3]triazol-4-yl)pyridine ligands determined the quantum yield of the resulting ruthenium(II) complexes remarkably. Separately, 2-([1,2,3]triazol-4-yl)pyridine ligands are known to be potential quenchers, but using these new ligand systems led to room temperature emission of the corresponding ruthenium(II) complexes. The compounds have been fully characterized by elemental analysis, high-resolution ESI mass spectrometry, (1)H and (13)C NMR spectroscopy, and X-ray crystallography. Theoretical calculations for two ruthenium(II) complexes bearing a donor and acceptor unit, respectively, were performed to gain a deeper understanding of the photophysical behavior.
authors.affiliation: Laboratory of Organic and Macromolecular Chemistry, Friedrich-Schiller-University Jena, Humboldtstrasse 10, 07743 Jena, Germany.
authors.forename: Bobby
authors.initials: B
authors.lastname: Happ
authors.forename: Daniel
authors.initials: D
authors.lastname: Escudero
authors.forename: Martin D
authors.initials: MD
authors.lastname: Hager
authors.forename: Christian
authors.initials: C
authors.lastname: Friebe
authors.forename: Andreas
authors.initials: A
authors.lastname: Winter
authors.forename: Helmar
authors.initials: H
authors.lastname: Görls
authors.forename: Esra
authors.initials: E
authors.lastname: Altuntaş
authors.forename: Leticia
authors.initials: L
authors.lastname: González
authors.forename: Ulrich S
authors.initials: US
authors.lastname: Schubert