CINECA IRIS Institutional Research Information System
IRIS è la soluzione IT che facilita la raccolta e la gestione dei dati relativi alle attività e ai prodotti della ricerca. Fornisce a ricercatori, amministratori e valutatori gli strumenti per monitorare i risultati della ricerca, aumentarne la visibilità e allocare in modo efficace le risorse disponibili.
EnglishThe complex formation between (VO)-O-IV and phosphonic derivatives of iminodiacetic (Ida) and nitrilotriacetic acids (Nta) has been studied by combined application of pH-potentiometric and spectroscopic (EPR and electronic absorption) techniques. Differently from aminomonophosphonates, which are able to bind the metal ion rather weakly forming five-membered chelated rings, the mixed carboxylic-phosphonic and pure phosphonic derivatives of Ida and Nta form chelated systems resulting in very stable complexes mostly of the 1 : 1 type. Substitution of CO2- by PO32- increases the stability of the complexes due to the higher basicities of the phosphonic functions. However, the higher spatial requirement of the phosphonate groups and the greater electrostatic repulsion between the dinegative phosphonate arms would mostly compensate this effect. Spectroscopic evidence has been found for a considerable distortion in the geometry of the aminophosphonate complexes. The differences in the observed stability trends between the corresponding copper(II) and (VO)-O-IV complexes are also discussed.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo
| Titolo: | Oxovanadium(IV) complexes of phosphonic derivatives of iminodiacetic and nitrilotriacetic acids |
| Autori: | |
| Data di pubblicazione: | 1999 |
| Rivista: | |
| Abstract: | The complex formation between (VO)-O-IV and phosphonic derivatives of iminodiacetic (Ida) and nitrilotriacetic acids (Nta) has been studied by combined application of pH-potentiometric and spectroscopic (EPR and electronic absorption) techniques. Differently from aminomonophosphonates, which are able to bind the metal ion rather weakly forming five-membered chelated rings, the mixed carboxylic-phosphonic and pure phosphonic derivatives of Ida and Nta form chelated systems resulting in very stable complexes mostly of the 1 : 1 type. Substitution of CO2- by PO32- increases the stability of the complexes due to the higher basicities of the phosphonic functions. However, the higher spatial requirement of the phosphonate groups and the greater electrostatic repulsion between the dinegative phosphonate arms would mostly compensate this effect. Spectroscopic evidence has been found for a considerable distortion in the geometry of the aminophosphonate complexes. The differences in the observed stability trends between the corresponding copper(II) and (VO)-O-IV complexes are also discussed. |
| Handle: | http://hdl.handle.net/11388/82990 |
| Appare nelle tipologie: | 1.1 Articolo in rivista |
File in questo prodotto:
Copyright © 2021