Energy-transfer processes in lanthanide dinuclear complexes with p-tert-butylcalix[8]arene. An example of dipole-dipolar mechanism

Journal Article · Thu Jan 13 04:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100053a030· OSTI ID:5182218

Froidevaux, P; Buenzli, J C.G. ^[1]

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1. Universite de Lausanne (Switzerland)

The study of energy-transfer processes between Tb(III) and various Ln(III) ions (Ln = Ho, Nd, Eu) in dinuclear complexes of p-tert-butylcalix[8]arene, [(Tb[sub x]Ln[sub 2[minus]x])(LH[sub 2])(DMF)[sub 5]][center dot]4DMF, is reported. Easily available crystals allow an extended work on these transfers. The compounds contain isolated molecules, so that a simple model accounts for the observed luminescence decays. Only two types of interacting Tb-Ln pairs need to be taken into account, one at 3.7 A and the other at 11 A. A rate equation is developed to quantify the energy transfer, and the analyzed data give an interaction strength sequence proportional to the overlap integral, F[sub Tb-Ho] > F[sub Tb-Nd] > F[sub Tb-Eu]. Moreover, the good fits obtained point unambiguously to a dipole-dipolar character of the energy-transfer processes. The low-lying ligand-to-metal charge-transfer state (LMCT) increases the absorption probabilities of Eu(III) f-f transitions considerably, and the resulting quasi-allowed [sup 5]D[sub o] [yields] [sup 7]F[sub o] transition plays an important role in the energy-transfer process. This feature permits us to assign a dipolar character to the interaction responsible for the energy transfer. The low-lying LMCT state also induces a strong intramolecular Eu-Eu interaction. 20 refs., 3 figs., 4 tabs.

• OSTI ID: 5182218
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:2; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
661300 -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AROMATICS
CHARGE STATES
CHARGE TRANSPORT
CHEMICAL REACTION KINETICS
COMPILED DATA
COMPLEXES
CRYSTALS
DATA
DIPOLES
ENERGY LEVELS
ENERGY TRANSFER
EUROPIUM COMPLEXES
EXCITED STATES
HOLMIUM COMPLEXES
INFORMATION
KINETICS
LIGANDS
LUMINESCENCE
MOLECULES
MULTIPOLES
NEODYMIUM COMPLEXES
NUMERICAL DATA
ORGANIC COMPOUNDS
RARE EARTH COMPLEXES
REACTION KINETICS
TERBIUM COMPLEXES