Intramolecular energy transfer in actinide complexes of 6-methyl-2-(2-pyridyl)-benzimidazole (biz): comparison between Cm{sup 3+} and Tb{sup 3+} systems

Journal Article · Tue Feb 15 04:00:00 EST 2005 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2004.09.017· OSTI ID:20721760

Assefa, Zerihun ^[1]; Yaita, T ^[2]; Haire, R G ^[1]; Tachimori, S ^[2]

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1. Transuranium Chemistry Group, Chemical Sciences Division, Oak Ridge National Laboratory, MS 6375, Oak Ridge, TN 37831-6375 (United States)
2. Department of Materials Science, Japan Atomic Energy Research Institute, Tokai (Japan)

Coordination of the 6-methyl-2-(2-pyridyl)-benzimidazole ligand with actinide and lanthanide species can produce enhanced emission due to increased efficiency of intramolecular energy transfer to metal centers. A comparison between the curium and terbium systems indicates that the position of the ligand's triplet state is critical for the enhanced emission. The energy gap between the ligand's triplet state and the acceptor level in curium is about 1000cm{sup -1}, as compared to a {approx}600cm{sup -1} gap in the terbium system. Due to the larger gap, the back transfer with curium is reduced and the radiative yield is significantly higher. The quantum yield for this 'sensitized' emission increases to 6.2%, compared to the 0.26% value attained for the metal centered excitation prior to ligand addition. In the terbium case, the smaller donor/acceptor gap enhances back transfer and the energy transfer is less efficient than with the curium system.

• OSTI ID: 20721760
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 178; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BENZIMIDAZOLES
COMPARATIVE EVALUATIONS
CURIUM COMPLEXES
CURIUM IONS
ENERGY GAP
ENERGY TRANSFER
EXCITATION
LIGANDS
PHOTOLUMINESCENCE
SPECTROSCOPY
TERBIUM COMPLEXES
TERBIUM IONS
TRIPLETS