Change search
ReferencesLink to record
Permanent link

Direct link
Structure and dynamics of binary and ternary lanthanide(III) and actinide(III) tris[4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione] (TTA) complexes. Part 2, the structure and dynamics of binary and ternary complexes in the Y(III)/Eu(III) -TTA - tributylphosphate (TBP) system in chloroform as studied by NMR spectroscopy
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.ORCID iD: 0000-0002-7552-1076
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
2010 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 39, no 45, 10944-10952 p.Article in journal (Refereed) Published
Abstract [en]

The stoichiometric reaction mechanisms, rate constants and activation parameters for inter-and intramolecular ligand exchange reactions in the binary Y/Eu(TTA)(3)(OH2)(2)-HTTA and the ternary Y/Eu(TTA)(3)(OH2)(2)-TBP systems have been studied in chloroform using H-1 and P-31 NMR methods. Most complexes contain coordinated water that is in very fast exchange with water in the chloroform solvent. The exchange reactions involving TTA/HTTA and TBP are also fast, but can be studied at lower temperature. The rate constant and activation parameters for the intramolecular exchange between two structure isomers in Y(TTA)(3)(OH2)(2) and Y(TTA)(3)(TBP)(OH2) were determined from the line-broadening of the methine protons in coordinated TTA. The rate equations for the intermolecular exchange between coordinated TTA and free HTTA in both complexes are consistent with a two-step mechanism where the first step is a fast complex formation of HTTA, followed by a rate determining step involving proton transfer from coordinated HTTA to TTA. The rate constants for both the interand intramolecular exchange reactions are significantly smaller in the TBP system. The same is true for the activation parameters in the Y(TTA)(3)(OH2)(2)-HTTA and the ternary Y/Eu(TTA)(3)(TBP)(OH2)-HTTA systems, which are Delta H-not equal = 71.8 +/- 2.8 kJ mol(-1), Delta S-not equal = 62.4 +/- 10.3 J mol(-1) K-1 and Delta H-not equal = 38.8 +/- 0.6 kJ mol(-1), Delta S-not equal = -93.0 +/- 3.3 J mol(-1) K-1, respectively. The large difference in the activation parameters does not seem to be related to a difference in mechanism as judged by the rate equation; this point will be discussed in a following communication. The rate and mechanism for the exchange between free and coordinated TBP follows a two-step mechanism, involving the formation of Y(TTA)(3)(TBP)(2).

Place, publisher, year, edition, pages
2010. Vol. 39, no 45, 10944-10952 p.
Keyword [en]
National Category
Chemical Sciences
URN: urn:nbn:se:kth:diva-27091DOI: 10.1039/c0dt00314jISI: 000284066100017ScopusID: 2-s2.0-78149442088OAI: diva2:376190
QC 20101210Available from: 2010-12-10 Created: 2010-12-06 Last updated: 2010-12-10Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Szabo, ZoltanGrenthe, Ingmar
By organisation
Organic ChemistryInorganic Chemistry
In the same journal
Dalton Transactions
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 35 hits
ReferencesLink to record
Permanent link

Direct link