Using the antenna effect as a spectroscopic tool: photophysics and solution thermodynamics of the model luminescent hydroxypyridonate complex [Eu(III)(3,4,3-LI(1,2-HOPO))]-.
Although widely used in bioassays, the spectrofluorimetric method described here uses the antenna effect as a tool to probe the thermodynamic parameters of ligands that sensitize lanthanide luminescence. The Eu(3+) coordination chemistry, solution thermodynamic stability, and photophysical properties of the spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) are reported. The complex [Eu(III)(3,4,3-LI(1,2-HOPO))](-) luminesces with a long lifetime (805 mus) and a quantum yield of 7.0% in aqueous solution, at pH 7.4. These remarkable optical properties were exploited to determine the high (and proton-independent) stability of the complex (log beta(110) = 20.2(2)) and to define the influence of the ligand scaffold on the stability and photophysical properties.
Abergel
Rebecca J
RJ
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
D'Aléo
Anthony
A
Leung
Clara Ng Pak
CN
Shuh
David K
DK
Raymond
Kenneth N
KN
D005063:Europium / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D049449:Luminescence; D008956:Models, Chemical; D015394:Molecular Structure; D010777:Photochemistry; D011789:Quantum Theory; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D018020:Lithium Compounds; D012996:Solutions; D005063:Europium