The acid–base and the UV behavior of 3-(3,4-dihydroxyphenyl)-propenoic acid (caffeic acid) was studied by potentiometry and UV spectrophotometry at T = 298.15 K and 0.1 ≤ I/mol L− 1 ≤ 1 in NaCl aqueous solution. The complex formation with Zn2 +, Cu2 +, Cd2 +, (CH3)2Sn2 + at I = 0.1 mol L− 1 in NaCl has been also determined by using potentiometric and spectrophotometric titration techniques. The results obtained by the spectrophotometric measurements fully confirm those obtained by potentiometry, with a particularly good agreement for the system containing Cu2 +. The results showed that, for the ML species, at I = 0.1 mol L− 1 in NaCl and T = 298.15 K, the stability of the caffeate-(CH3)2Sn2 +, and -Cu2 + species is high, with logβML = 16.577 and 13.05, respectively, while that of the caffeate-Zn2 + and -Cd2 + species is considerably lower, with logβML = 8.526 and 7.272, respectively. Speciation profiles for all the systems under study were also calculated and sequestering ability of the caffeate towards the different metal cations considered in this investigation was also evaluated. For example, at physiological pH, I = 0.1 mol L− 1 in NaCl and T = 298.15 K, the order of sequestering ability is Cu2 + > (CH3)2Sn2 + > Zn2 + > Cd2 +.

Acid-base and UV behaviour of 3-(3,4-dihydroxyphenyl)-propenoic acid (caffeic acid) and complexing ability towards different divalent metal cations in aqueous solution

DE STEFANO, Concetta;FOTI, Claudia;GIUFFRE', Ottavia
;
SAMMARTANO, Silvio
2014-01-01

Abstract

The acid–base and the UV behavior of 3-(3,4-dihydroxyphenyl)-propenoic acid (caffeic acid) was studied by potentiometry and UV spectrophotometry at T = 298.15 K and 0.1 ≤ I/mol L− 1 ≤ 1 in NaCl aqueous solution. The complex formation with Zn2 +, Cu2 +, Cd2 +, (CH3)2Sn2 + at I = 0.1 mol L− 1 in NaCl has been also determined by using potentiometric and spectrophotometric titration techniques. The results obtained by the spectrophotometric measurements fully confirm those obtained by potentiometry, with a particularly good agreement for the system containing Cu2 +. The results showed that, for the ML species, at I = 0.1 mol L− 1 in NaCl and T = 298.15 K, the stability of the caffeate-(CH3)2Sn2 +, and -Cu2 + species is high, with logβML = 16.577 and 13.05, respectively, while that of the caffeate-Zn2 + and -Cd2 + species is considerably lower, with logβML = 8.526 and 7.272, respectively. Speciation profiles for all the systems under study were also calculated and sequestering ability of the caffeate towards the different metal cations considered in this investigation was also evaluated. For example, at physiological pH, I = 0.1 mol L− 1 in NaCl and T = 298.15 K, the order of sequestering ability is Cu2 + > (CH3)2Sn2 + > Zn2 + > Cd2 +.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/3069385
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 27
  • ???jsp.display-item.citation.isi??? 23
social impact