Different Complexation Properties of Some Hydroxy Keto Heterocycles toward Beryllium(II)in Aqueous Solutions: Experimental and Theoretical Studies (Articolo in rivista)

Type
Label
  • Different Complexation Properties of Some Hydroxy Keto Heterocycles toward Beryllium(II)in Aqueous Solutions: Experimental and Theoretical Studies (Articolo in rivista) (literal)
Anno
  • 2002-01-01T00:00:00+01:00 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
  • 10.1021/ic025612u (literal)
Alternative label
  • Cecconi, Franco; Ghilardi, Carlo A.; Ienco, Andrea; Mariani, Palma; Mealli, Carlo; Midollini, Stefano; Orlandini, Annabella; Vacca, Alberto (2002)
    Different Complexation Properties of Some Hydroxy Keto Heterocycles toward Beryllium(II)in Aqueous Solutions: Experimental and Theoretical Studies
    in Inorganic chemistry
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Cecconi, Franco; Ghilardi, Carlo A.; Ienco, Andrea; Mariani, Palma; Mealli, Carlo; Midollini, Stefano; Orlandini, Annabella; Vacca, Alberto (literal)
Pagina inizio
  • 4006 (literal)
Pagina fine
  • 4017 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni
  • Il berillio è un metallo che trova un sempre più largo impiego in applicazioni di alta tecnologia. Purtroppo il metallo è estremamente tossico ed il meccanismo molecolare con cui le cellule vengono attaccate è ancora sconosciuto e non esistono antidoti di accertata validità terapeutica. Fattore di impatto del giornale 2.950 (2002). (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 41 (literal)
Rivista
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#descrizioneSinteticaDelProdotto
  • Speciazione dei complessi formati da una serie di molecole di interesse terapeutico con lo ione tossico berillio(II) in soluzione acquosa e valutazione delle capacità sequestranti di questi leganti nei confronti dello ione. Viene mostrato in generale come leganti di analoga struttura e capacità chelanti comparabili nei riguardi dello ione berillio(II) debbano essere scelti con cura sulla base di fattori anche sottilmente diversi. (literal)
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • 1 CNR, 2 CNR, 3 CNR, 4 Uni Firenze, 5 CNR, 6 CNR, 7 CNR, 8 Uni Firenze (literal)
Titolo
  • Different Complexation Properties of Some Hydroxy Keto Heterocycles toward Beryllium(II)in Aqueous Solutions: Experimental and Theoretical Studies (literal)
Abstract
  • Four heterocycles containing hydroxy and keto functionalities have been tested as chelating agents of beryllium(II). These are in the order (i) 3-hydroxy-2-methyl-4H-pyran-4-one(maltol, Hma), (ii) 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one (kojic acid, Hka), (iii) 3-hydroxy-1,2-dimethyl-4-pyridinone (Hdpp), (iV) 1-(3-hydroxy-2-furanyl)ethanone (isomaltol, Hima). Although the skeletons of the first three species, with one nitrogen or oxygen heteroatom at the six-membered ring, are almost superimposable, straighforward synthesis and crystallization is achieved only for the 1:2 adduct Be(dpp)2, 1. Also the complex Be(ima)2, 2, precipitates in high yield but the ima- ligand has a different skeletal structure. X-ray determinations of 1 and 2 showed that the Be2+ ion is pseudotetrahedrally coordinated by two chelating ligands with slightly asymmetric Be-Oalkoxo and Be-Oketo bonds. The complex Be(ma)2 precipitates in low yields together with large amounts of unreacted Hma while, under the same conditions, no trace of the analogous species Be(ka)2 has been observed. This paper presents the results of potentiometric and NMR studies in the aqueous solutions as well as of DFT structural optimizations for all of the free acids, their associated bases, and the adducts of the type [BeL(H2O)2]+ and BeL2 in the gas phase. It is consistently found that the basicity of the ligands and the stability of their complexes decrease in the order dpp->ma->ka->ima-. In solution, all of the anionic ligands form adducts of the type [BeL(H2O)2]+ at low pH values, whereas higher concentrations of the free anion are required to form 1:2 adducts. The pH, the basicity, and the stability constants of the complexes as well as the formation of competing beryllium hydroxide species are strictly correlated factors for the obtainment of the latter type of adduct. The DFT calculations account nicely for the different donor powers of the various chelates in terms of electronic redistribution and associated energetics. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Prodotto
Autore CNR di
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it