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

Journal Article · Thu Jan 13 00:00:00 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), Vol. 98:2; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

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