Excitation and deexcitation processes of Eu(III) benzo-15-crown-5 complex studied on comparing with its first coordination sphere

Tomoo Yamamura, Wataru Sugiyama, Hiroyasu Hotokezaka, Masayuki Harada, Hiroshi Tomiyasu, Yoshiyuki Nakamura

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

The coordination sphere and the deexcitation mechanism of the Eu(III) benzo-15-crown-5 complex, Eu(B15C5), were studied with references of the Eu(III) complexes with a similar coordination sphere; the dibenzo-18-crown-6 complex, Eu3(B218C6)2, and the cryptand[2.2.1] complex, Eu([2.2.1]). NMR spectroscopy reveals that the Eu(B15C5) complex is quite stable in acetonitrile solution whereas only 40% of the Eu(III) ion forms the complex in the equimolar Eu(NO3)3 and B218C6 acetonitrile solution. The coordination sphere of the Eu(III) complexes in acetonitrile solutions were also discussed by the degenerate 7F05D0 transition energy levels. The Eu(B15C5) have a negative shift compared with the europium(III) nitrate in acetonitrile and it is explained by the coordination of both nitrate ions and the crown ether ligand. Energy transfer from the n - π* excited state located in the catechol structure to the central europium ion was first observed as the sensitized luminescence of 5D07FJ. The excited state lifetime of the Eu(B15C5) complex was first determined as 201 μs in the present study.

Original languageEnglish
Pages (from-to)75-82
Number of pages8
JournalInorganica Chimica Acta
Volume320
Issue number1-2
DOIs
Publication statusPublished - 2001 Aug 13

Keywords

  • Coordination sphere
  • Deexcitation mechanism
  • Europium(III) benzo-15-crown complexes
  • Excited state lifetime

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Excitation and deexcitation processes of Eu(III) benzo-15-crown-5 complex studied on comparing with its first coordination sphere'. Together they form a unique fingerprint.

Cite this