Six-membered ring chelate complexes of Ru(II): Structural and photophysical effects

Maria Abrahamsson, Hans Christian Becker, Leif Hammarström, Celine Bonnefous, Charles Chamchoumis, Randolph P. Thummel

Research output: Contribution to journalArticlepeer-review

52 Citations (Scopus)


The structural and photophysical properties of Ru(II)-polypyridyl complexes with five- and six-membered chelate rings were studied for two bis-tridentate and two tris-bidentate complexes. The photophysical effect of introducing a six-membered chelate ring is most pronounced for the tridentate complex, leading to a room-temperature excited-state lifetime of 810 ns, a substantial increase from 180 ns for the five-membered chelate ring model complex. Contrasting this, the effect is the opposite in tris-bidentate complexes, in which the lifetime decreases from 430 ns to around 1 ns in going from a five-membered to six-membered chelate ring. All of the complexes were studied spectroscopically at both 80 K and ambient temperatures, and the temperature dependence of the excited-state lifetime was investigated for both of the bis-tridentate complexes. The main reason for the long excited-state lifetime in the six-membered chelate ring bis-tridentate complex was found to be a strong retardation of the activated decay via metal-centered states, largely due to an increased ligand field splitting due to the complex having a more-octahedral geometry.

Original languageEnglish
Pages (from-to)10354-10364
Number of pages11
JournalInorganic Chemistry
Issue number24
Publication statusPublished - Nov 26 2007

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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