Relaxation process of CT exciton state in a one-dimensional MX-chain compound [NiBr(chxn)2]Br2

Shinya Takaishi, Hiroshi Kitagawa, Ryuichi Ikeda

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Luminescence spectroscopy measurements were performed in a one-dimensional halogen-bridged transition-metal compound [NiBr(chxn)2]Br2 (chxn: 1R,2R-cyclohexanediamine) and its mixed-metal compound [Ni 1-xPdxBr(chxn)2]Br2 with x = 0.005, 0.05, 0.33. The broad peaks were observed at 1.3 and 1.4 eV for [NiBr(chxn) 2]Br2, which are attributed to a relaxation of LMCT exciton state and a hot luminescence, respectively. No Stokes shift of the luminescence at 1.3 eV was observed, which shows the electron-lattice interaction (S) is weak in this system. From the temperature dependence of luminescence spectra, it was clarified that the relaxation process is continuously changed from luminescence to thermal relaxation. The luminescence peak at 1.3 eV is remarkably quenched with increase of x for [Ni 1-xPdxBr(chxn)2]Br2, implying that the LMCT exciton is trapped to in-gap states caused by doped Pd3+.

Original languageEnglish
Pages (from-to)279-284
Number of pages6
JournalMolecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals
Volume379
Publication statusPublished - 2002 Dec 1
Externally publishedYes

Keywords

  • Charge-transfer exciton
  • Luminescence
  • MX chain
  • Mixed valence

ASJC Scopus subject areas

  • Condensed Matter Physics

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