Paramagnetic metal effect on the ligand localized S/sub 1/. -->. T/sub 1/ intersystem crossing in the rare-earth-metal complexes and methyl salicylate

Journal Article · Tue Jan 01 04:00:00 EST 1985 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100272a015· OSTI ID:5813918

Tobita, S; Arakawa, M; Tanaka, I

The electronic relaxation processes in the chelates of La/sup 3 +/, Gd/sup 3 +/, Tb/sup 3 +/, and Lu/sup 3 +/ with methyl salicylate have been investigated by measurements of picosecond fluorescence, nanosecond transient absorptions, and quantum yields. The quantum yields of the S/sub 1/ ..-->.. T/sub 1/ intersystem crossing are not appreciably altered by a change in the central metal ions. However, the fluorescence lifetimes are decreased dramatically in the paramagnetic Gd/sup 3 +/ (240 ps) and Tb/sup 3 +/ (<10 ps) complexes compared with those in the diamagnetic La/sup 3 +/ (2.2 ns) and Lu/sup 3 +/ (2.4 ns) complexes. The rate constants derived from these results for the S/sub 1/ ..-->.. T/sub 1/ intersystem crossing, k/sub TM/, in ligands are 5.5 x 10/sup 7/, 7.5 x 10/sup 8/, and 7.9 x 10/sup 7/ s/sup -1/ for the La/sup 3 +/, Gd/sup 3 +/, and Lu/sup 3 +/ complexes, respectively. A large increase of k/sub TM/ is observed in the paramagnetic Gd/sup 3 +/ complexes, which can be attributed to the electron exchange mechanism with ligand ..pi.. electrons. 27 references, 8 figures, 3 tables.

• Research Organization: Gunma Technical College, Japan
• OSTI ID: 5813918
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 89:26; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
&amp; Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
CHELATES
CHEMICAL REACTION KINETICS
CHEMISTRY
COMPLEXES
DATA
DIAMAGNETISM
ELECTRON TRANSFER
EMISSION SPECTROSCOPY
ENERGY LEVELS
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
GADOLINIUM COMPLEXES
HYDROXY ACIDS
INFORMATION
IONS
KINETICS
LANTHANUM COMPLEXES
LIFETIME
LIGANDS
LUTETIUM COMPLEXES
MAGNETISM
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
PARAMAGNETISM
PHOTOCHEMISTRY
RARE EARTH COMPLEXES
REACTION KINETICS
SALICYLIC ACID
SPECTROSCOPY
TERBIUM COMPLEXES
TIME DEPENDENCE
TIME MEASUREMENT
TRANSIENTS