• español
    • English
  • Login
  • English 
    • español
    • English

UniversidaddeCádiz

Área de Biblioteca, Archivo y Publicaciones
Communities and Collections
View Item 
  •   RODIN Home
  • Institutos de Investigación
  • Instituto de Investigación en Biomoléculas INBIO
  • Artículos Científicos INBIO
  • View Item
  •   RODIN Home
  • Institutos de Investigación
  • Instituto de Investigación en Biomoléculas INBIO
  • Artículos Científicos INBIO
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Equilibrium, Kinetic, and Computational Studies on the Formation of Cu2+ and Zn2+ Complexes with an Indazole-Containing Azamacrocyclic Scorpiand: Evidence for Metal-Induced Tautomerism

Thumbnail
Identificadores

URI: http://hdl.handle.net/10498/20480

DOI: 10.1021/ic5029004

Files
2015-Equilibrium, kinetic, and computational studies on the formation of Cu2+ and Zn2+ complexes with an indazole-containing azamacrocyclic scorpiand. Evidence for metal-induced tauto.pdf (2.552Mb)
Statistics
View statistics
Metrics and citations
 
Share
Export
Export reference to MendeleyRefworksEndNoteBibTexRIS
Metadata
Show full item record
Author/s
Verdejo, Begoña; Acosta-Rueda, Laura; Clares, M. Paz; Aguinaco Martín, AlmudenaAuthority UCA; García Basallote, ManuelAuthority UCA; Soriano, Concepción; Tejero, Roberto; García-España, Enrique
Date
2015
Department
Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
Source
Inorganic Chemistry 2015, 54, 1983−1991
Abstract
Cu2+ and Zn2+ coordination chemistry of a new member of the family of scorpiand-like macrocyclic ligands derived from tris(2-aminoethyl)amine (tren) is reported. The new ligand (L1) contains in its pendant arm not only the amine group derived from tren but also a 6-indazole ring. Potentiometric studies allow the determination of four protonation constants. UV−vis and fluorescence data support that the last protonation step occurs on the indazole group. Equilibrium measurements in the presence of Cu2+ and Zn2+ reveal the formation of stable [ML1]2+, [MHL1]3+, and [ML1(OH)]+ complexes. Kinetic studies on the acid-promoted decomposition of the metal complexes were carried out using both absorbance and fluorescence detection. For Zn2+, both types of detection led to the same results. The experiments suggest that [ZnL1]2+ protonates upon addition of an acid excess to form [ZnHL1]3+ within the mixing time of the stopped-flow instrument, which then decomposes with a first-order dependence on the acid concentration. The kinetic behavior is more complex in the case of Cu2+. Both [CuL1]2+ and [CuHL1]3+ show similar absorption spectra and convert within the mixing time to a new intermediate species with a band at 750 nm, the process being reverted by addition of base. The intermediate then decomposes with a secondorder dependence on the acid concentration. However, kinetic experiments with fluorescence detection showed the existence of an additional faster step. With the help of DFT calculations, an interpretation is proposed in which protonation of [CuL1]2+ to form [CuHL1]3+ would involve dissociation of the tren-based NH group in the pendant arm and coordination of a 2H-indazole group. Further protonation would lead to dissociation of coordinated indazole, which then will convert to the more stable 1H tautomer in a process signaled by fluorescence changes that would not be affecting to the d−d spectrum of the complex.
Collections
  • Artículos Científicos [4846]
  • Articulos Científicos CC. Mat. [195]
  • Artículos Científicos INBIO [264]
Attribution-NonCommercial-NoDerivatives 4.0 Internacional
This work is under a Creative Commons License Attribution-NonCommercial-NoDerivatives 4.0 Internacional

Browse

All of RODINCommunities and CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

LoginRegister

Statistics

View Usage Statistics

Información adicional

AboutDeposit in RODINPoliciesGuidelinesRightsLinksStatisticsNewsFrequently Asked Questions

RODIN is available through

OpenAIREOAIsterRecolectaHispanaEuropeanaBaseDARTOATDGoogle Academic

Related links

Sherpa/RomeoDulcineaROAROpenDOARCreative CommonsORCID

RODIN está gestionado por el Área de Biblioteca, Archivo y Publicaciones de la Universidad de Cádiz

Contact informationSuggestionsUser Support