Spectroscopic Characterization of a Series of Europium(III) Amino Phosphonate Complexes in Solution

Authors

Richard C. Holz, Marquette UniversityFollow
Gretchen E. Meister, Pennsylvania State University - Main Campus
William DeW Horrocks Jr, Pennsylvania State University - Main Campus

Document Type

Article

Publication Date

12-1990

Source Publication

Inorganic Chemistry

Source ISSN

0020-1669

Abstract

The Eu³⁺ complexes of nitrilotris (methylenephosphonic acid) (ntp), ethylenediaminetetrakis (methylenephosphonic acid) (edtp), hexamethylenediaminetetrakis (methylenephosphonic acid) (hdtp), and diethylenetriaminepentakis (methylenephosphonic acid) (dtpp) have been characterized in solution by laser-induced Eu³⁺ luminescence spectroscopy. The latter three ligands form both 2:1 and 1:1 metal-ligand complexes, while ntp forms both 1:1 and 1:2 complexes at pH 6.0. The number of water molecules directly coordinating the metal ion was determined for each complex. The ⁷F₀ -> ⁵D₀ excitation spectra of edtp, hdtp, and dtpp reveal isomeric forms for both the 2:1 and 1:1 complexes while ntp exhibits only single species for both the 1:1 and 1:2 complexes. Marked changes were observed in the Eu^{3+ 7}F₀ -> ⁵D₀ excitation spectra of the various species as a function of pH. The temperature dependence of the xcited state lifetime of the Eu³⁺-edtp system has an activation energy of 5150 cm^-1, corresponding to a ligand level this far above the ⁵D₀ state, which is involved in the deexcitation process.

Comments

Inorganic Chemistry, Vol. 29, No. 26 (December 1990): 5183-5189. DOI.

Richard Holz was affiliated with the Pennsylvania State University at the time of publication.

Recommended Citation

Holz, Richard C.; Meister, Gretchen E.; and Horrocks, William DeW Jr, "Spectroscopic Characterization of a Series of Europium(III) Amino Phosphonate Complexes in Solution" (1990). Chemistry Faculty Research and Publications. 299.
https://epublications.marquette.edu/chem_fac/299