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Title: Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide

Abstract

The thermodynamic parameters of complexation of Ln(III) cations with tris(2-aminoethyl)amine (tren) and tetraethylenepentamine (tetren) were determined in dimethyl sulfoxide (DMSO) by potentiometry and calorimetry. The excitation and emission spectra and luminescence decay constants of Eu 3+ and Tb 3+ complexed by tren and tetren, as well as those of the same lanthanides(III) complexed with diethylenetriamine (dien) and triethylenetetramine (trien), were also obtained in the same solvent. The combination of thermodynamic and spectroscopic data showed that, in the 1:1 complexes, all nitrogens of the ligands bound to the lanthanides except in the case of tren, in which only pendant N bound. For the larger ligands (trien, tren, tetren) in the higher complexes (ML 2), there was less complete binding by available donors, presumably due to steric crowding. FT-IR studies were carried out in an acetonitrile/DMSO mixture, suitably chosen in order to follow the changes in the primary solvation sphere of lanthanide(III) due to complexation of amine ligands. Results show that the mean number of molecules of DMSO removed from the inner coordination sphere of lanthanides(III) is lower than ligand denticity and that the coordination number of the metal ions increases with amine complexation from ~8 to ~10. Independently of the numbermore » and structure of the amines, linear trends, similar for all lanthanides, were obtained by plotting the values of ΔGj°, ΔHj° and TΔSj° for the complexation of ethylenediamine (en), dien, trien, tren and tetren as a function of the number of amine metal-coordinated nitrogen atoms. The main factors on which the thermodynamic functions of lanthanide(III) complexation reactions in DMSO depend are discussed.« less

Authors:
 [1];  [1];  [2];  [2];  [2];  [3];  [4]
  1. Univ. of Padova (Italy)
  2. Univ. of Udine (Italy)
  3. Florida State Univ., Tallahassee, FL (United States)
  4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
924657
Report Number(s):
PNNL-SA-55527
Journal ID: ISSN 0020-1669; INOCAJ; TRN: US200809%%319
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Inorganic Chemistry; Journal Volume: 47; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AMINES; THERMODYNAMIC PROPERTIES; LANTHANUM COMPLEXES; DMSO; CALORIMETRY; COORDINATION NUMBER; POTENTIOMETRY; EUROPIUM COMPLEXES; TERBIUM COMPLEXES; Lanthanides; polyamine; formation constants; thermodynamics; solvation; dimethyl sulfoxide; spectroscopy

Citation Formats

Di Bernardo, Plinio, Zanonato, Pier Luigi, Melchior, Andrea, Portanova, Roberto, Tolazzi, Marilena, Choppin, Gregory R., and Wang, Zheming. Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide. United States: N. p., 2008. Web. doi:10.1021/ic701337u.
Di Bernardo, Plinio, Zanonato, Pier Luigi, Melchior, Andrea, Portanova, Roberto, Tolazzi, Marilena, Choppin, Gregory R., & Wang, Zheming. Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide. United States. doi:10.1021/ic701337u.
Di Bernardo, Plinio, Zanonato, Pier Luigi, Melchior, Andrea, Portanova, Roberto, Tolazzi, Marilena, Choppin, Gregory R., and Wang, Zheming. Tue . "Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide". United States. doi:10.1021/ic701337u.
@article{osti_924657,
title = {Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide},
author = {Di Bernardo, Plinio and Zanonato, Pier Luigi and Melchior, Andrea and Portanova, Roberto and Tolazzi, Marilena and Choppin, Gregory R. and Wang, Zheming},
abstractNote = {The thermodynamic parameters of complexation of Ln(III) cations with tris(2-aminoethyl)amine (tren) and tetraethylenepentamine (tetren) were determined in dimethyl sulfoxide (DMSO) by potentiometry and calorimetry. The excitation and emission spectra and luminescence decay constants of Eu3+ and Tb3+ complexed by tren and tetren, as well as those of the same lanthanides(III) complexed with diethylenetriamine (dien) and triethylenetetramine (trien), were also obtained in the same solvent. The combination of thermodynamic and spectroscopic data showed that, in the 1:1 complexes, all nitrogens of the ligands bound to the lanthanides except in the case of tren, in which only pendant N bound. For the larger ligands (trien, tren, tetren) in the higher complexes (ML2), there was less complete binding by available donors, presumably due to steric crowding. FT-IR studies were carried out in an acetonitrile/DMSO mixture, suitably chosen in order to follow the changes in the primary solvation sphere of lanthanide(III) due to complexation of amine ligands. Results show that the mean number of molecules of DMSO removed from the inner coordination sphere of lanthanides(III) is lower than ligand denticity and that the coordination number of the metal ions increases with amine complexation from ~8 to ~10. Independently of the number and structure of the amines, linear trends, similar for all lanthanides, were obtained by plotting the values of ΔGj°, ΔHj° and TΔSj° for the complexation of ethylenediamine (en), dien, trien, tren and tetren as a function of the number of amine metal-coordinated nitrogen atoms. The main factors on which the thermodynamic functions of lanthanide(III) complexation reactions in DMSO depend are discussed.},
doi = {10.1021/ic701337u},
journal = {Inorganic Chemistry},
number = 3,
volume = 47,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 2008},
month = {Tue Jan 01 00:00:00 EST 2008}
}
  • No abstract prepared.
  • New viologen derivatives having the various para-substituted benzophenone groups connected with a -(CH{sub 2}){sub 3}-linkage were effectively photoreduced by dimethyl sulfoxide by the intramolecular charge transfer complex formation between the viologen and benzophenone groups through effective stacking. The photoreduction was enhanced by the introduction of electron-donating para-substituents on the benzophenone units which were favorable for the intramolecular charge transfer complexation. 6 refs., 5 figs.
  • Lanthanide selenidostannates (H{sub 3}O){sub n}[Ce(tepa)(μ-1κ{sup 2}:2κ{sup 2}-Sn{sub 2}Se{sub 6})]{sub n} (1), [(Yb(tepa)(μ-OH)){sub 2}(μ-1κ:2κ-Sn{sub 2}Se{sub 6})]{sub n}·nH{sub 2}O (2), [Htrien]{sub 2}[(Ln(trien)(tren)){sub 2}(μ-1κ:2κ-Sn{sub 2}Se{sub 6})][Sn{sub 2}Se{sub 6}] (Ln=Ce(3), Nd(4)) and [(Yb(dien){sub 2}){sub 2}(μ-OH){sub 2}]Sn{sub 2}Se{sub 6} (5) were solvothermally prepared in different ethylene polyamines. The Sn{sub 2}Se{sub 6} unit connects [Ce(tepa)]{sup 3+} and [(Yb(tepa)(μ-OH)){sub 2}]{sup 4+} fragments with tetradentate μ-1κ{sup 2}Se{sup 1},Se{sup 2}:2κ{sup 2}Se{sup 5},Se{sup 6} and bidentate μ-1κSe{sup 1}:2κSe{sup 5} bridging coordination modes in tepa, to form polymers 1 and 2, respectively. It joins two [Ln(trien)(tren)]{sup 3+} fragments as a μ-1κSe{sup 1}:2κSe{sup 5} ligand to form binuclear complexes 3 and 4more » in trien. Unlike the Sn{sub 2}Se{sub 6} units in 1–4 that bind with Ln(III) centers as Se-donor ligands, the Sn{sub 2}Se{sub 6} unit in 5 exists as a discrete ion. The syntheses of 1–5 show that the ethylene polyamines play an important role in the complexation of Sn{sub 2}Se{sub 6} ligand with Ln(III) centers. Compounds 1–5 exhibit optical band gaps in the range of 2.09–2.42 eV, which are influenced by the complexation of Sn{sub 2}Se{sub 6} with Ln(III) centers. - Graphical abstract: New lanthanide complexes concerning the Sn{sub 2}Se{sub 6} ligand were solvothermally prepared, and the effect of ethylene polyamines on the complexation of Sn{sub 2}Se{sub 6} with Ln(III) centers are observed. Highlights: • Lanthanide complexes concerning the selenidostannates have been solvothermally prepared in different ethylene polyamines. • A tetradentate μ-1κ{sup 2}Se{sup 1},Se{sup 2}:2κ{sup 2}Se{sup 5},Se{sup 6} and a bidentate μ-1κSe{sup 1}:2κSe{sup 5} bridging coordination modes for the Sn{sub 2}Se{sub 6} ligand is obtained. • The complexation of the Sn{sub 2}Se{sub 6} ligand with Ln(III) centers are influenced by the ethylene polyamines.« less
  • Log K, {Delta}H, and {Delta}S values for interactions of a series of pyridinoazacrown ethers each bearing a phenol arm (2-6) and two macrocycles each bearing a pyridine arm (7, 8) with Na{sup +}, K{sup +}, Tl{sup +}, and Ag{sup +} have been determined in absolute methanol at 25{degrees}C by calorimetric titration. In each case, the complex stability has the sequence Na{sup +} < K {sup +} < Tl{sup +} {much_lt} Ag{sup +}. The phenol-armed macrocycles exhibit selectivity of more than 4 orders of magnitude for Ag{sup +} over Na{sup +}, K{sup +}, and Tl{sup +}. Attachment of a pendant phenolmore » arm having various substituents to parent macrocycle 1 increases the binding abilities of the resulting ligands. Substituents on the para position of the phenol arm have an appreciable effect on cation-binding constants. Good Hammett correlations are found by plotting log K values vs {sigma}{sub p} for interactions of five phenol-armed macrocyclic ligands (2-6) with Na{sup +}, K{sup +}, and Tl{sup +}. The complexation has been characterized by means of {sup 1}H NMR and UV-visible spectroscopic, and X-ray crystallographic methods. The study indicates that the phenol OH group of 2-6 is capable of forming an intramolecular hydrogen bond with the macroring nitrogen atom and that the complexation in absolute methanol generally does not deprotonate these phenols. In the crystal structure of the Na{sup +} -3 complex, the Na{sup +} is coordinated to all seven of the donor atoms of the ligand and two Na{sup +} -3 complexes join together to form a dimer. The dimer contains an intermolecular hydrogen bond formed between the phenol hydrogen atom of one ligand and the phenolate group of a centrosymmetrically related ligand and two {pi}-{pi} stacking interactions between the electron-deficient pyridine ring of one molecule and the electron-rich phenol ring of the other. 36 refs., 5 figs., 6 tabs.« less