Solution structures of europium(III) complexes of ethylenediaminetetraacetic acid

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Journal of Coordination Chemistry

DOI:https://doi.org/10.1080/00958979608022693· OSTI ID:482432

Latva, M; Kankara, J; Haapakka, K ^[1]

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1. Univ. of Turku (Finland)

Coordination of ethylenediaminetetraacetic acid (EDTA) with europium(III) has been studied at different concentrations in solution using {sup 7}F{sub 0}{yields}{sup 5}D{sub 0} excitation spectroscopy and excited-state lifetime measurements. EDTA forms with Eu(III) ion three different species in equimolar solutions at room temperature. At low pH values EuEDTAH is formed and at higher pH values than 1.5 two EuEDTA{sup -} complexes, which differ from each other with one water molecule in the first coordination sphere of the Eu(III) ion, total coordination number and coordination geometry, are also formed. When the concentration of EDTA is higher than the concentration of Eu(III), an EuEDTA(EDTAH){sup 4-} species where the second EDTA is weakly coordinated to EuEDTA{sup -}, is formed. If the concentration of Eu(III) ion is higher than EDTA, the extra Eu(III) ions associate with EuEDTA{sup -} and link to one of the carboxylate groups of EDTA thus causing a shortening of the excited-state lifetime of the EuEDTA{sup -} complex.

• Sponsoring Organization: USDOE
• OSTI ID: 482432
• Journal Information: Journal of Coordination Chemistry, Journal Name: Journal of Coordination Chemistry Journal Issue: 1-2 Vol. 38; ISSN JCCMBQ; ISSN 0095-8972
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CONCENTRATION RATIO
EDTA
EMISSION SPECTROSCOPY
EUROPIUM COMPLEXES
STRUCTURAL CHEMICAL ANALYSIS