Show simple item record

dc.contributor.authorRoca Sabio, Adrián
dc.contributor.authorMato-Iglesias, Marta
dc.contributor.authorEsteban-Gómez, David
dc.contributor.authorBlas, Andrés de
dc.contributor.authorRodríguez-Blas, Teresa
dc.contributor.authorPlatas-Iglesias, Carlos
dc.date.accessioned2017-10-27T13:04:21Z
dc.date.available2017-10-27T13:04:21Z
dc.date.issued2011-01-14
dc.identifier.citationThe effect of ring size variation on the structure and stability of lanthanide(III) complexes with crown ethers containing picolinate pendants. A. Roca-Sabio, M. Mato-Iglesias, D. Esteban-Gómez, A. de Blas, T. Rodríguez-Blas and C. Platas-Iglesias, Dalt. Trans., 2011, 40, 384–392.es_ES
dc.identifier.issn1477-9226
dc.identifier.issn1477-9234
dc.identifier.urihttp://hdl.handle.net/2183/19648
dc.description.abstract[Abstract] The coordination properties of the macrocyclic receptor N,N′-bis[(6-carboxy-2-pyridyl)methylene]-1,10-diaza-15-crown-5 (H2bp15c5) towards the lanthanide ions are reported. Thermodynamic stability constants were determined by pH-potentiometric titration at 25 °C in 0.1 M KCl. A smooth decrease in complexstability is observed upon decreasing the ionic radius of the LnIII ion from La [log KLaL = 12.52(2)] to Lu [log KLuL = 10.03(6)]. Luminescence lifetime measurements recorded on solutions of the EuIII and TbIII complexes confirm the absence of inner-sphere watermolecules in these complexes. 1H and 13C NMR spectra of the complexes formed with the diamagnetic LaIII metal ion were obtained in D2O solution and assigned with the aid of HSQC and HMBC 2D heteronuclear experiments, as well as standard 2D homonuclear COSY and NOESY spectra. The 1H NMR spectra of the paramagnetic CeIII, EuIII and YbIIIcomplex suggest nonadentate binding of the ligand to the metal ion. The syn conformation of the ligand in [Ln(bp15c5)]+ complexes implies the occurrence of two helicities, one associated with the layout of the picolinate pendant arms (absolute configuration Δ or Λ), and the other to the five fivemembered chelate rings formed by the binding of the crown moiety (absolute configuration δ or λ). A detailed conformational analysis performed with the aid of DFT calculations (B3LYP model) indicates that the complexes adopt a Λ(λδ)(δδλ) [or Δ(δλ)(λλδ)] conformation in aqueous solution. Our calculations show that the interaction between the LnIII ion and several donor atoms of the crown moiety is weakened as the ionic radius of the metal ion decreases, in line with the decrease of complex stability observed on proceeding to the right across the lanthanide series.es_ES
dc.description.sponsorshipMinisterio de Educación y Ciencia; CTQ2006-07875es_ES
dc.description.sponsorshipMinisterio de Educación y Ciencia; CTQ2009-10721es_ES
dc.description.sponsorshipGalicia. Consellería de Economía e Industria; INCITE09E1R103013ESes_ES
dc.language.isoenges_ES
dc.publisherRoyal Society of Chemistryes_ES
dc.relation.urihttps://doi.org/10.1039/C0DT00746Ces_ES
dc.subjectPicolinate ligandses_ES
dc.subjectCrystal structureses_ES
dc.subjectLanthanide complexeses_ES
dc.subjectCrown etherses_ES
dc.subjectStability in solutiones_ES
dc.titleThe effect of ring size variation on the structure and stability of lanthanide(III) complexes with crown ethers containing picolinate pendantses_ES
dc.typeinfo:eu-repo/semantics/articlees_ES
dc.rights.accessinfo:eu-repo/semantics/openAccesses_ES
UDC.journalTitleDalton Transactionses_ES
UDC.volume40es_ES
UDC.issue2es_ES
UDC.startPage384es_ES
UDC.endPage392es_ES


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record