Binding of fluoride and carbonate by open chain polyammonium cations.
The formation of open chain polyammonium cation-fluoride and -carbonate complexes was studied by potentiometric and calorimetric techniques at t=25 degrees C. Several species of H(i)AL (A=amine; L=F(-), CO(3)(2-)) are formed in both systems with a mean stability log K=1.0zeta (zeta=|z(anion)xz(cation)|) and log K=2.0zeta for fluoride and carbonate, respectively. The comparison with analogous systems (chloride and acetate for fluoride and hydrogenphosphate, sulfate and malonate for carbonate) showed that fluoride and carbonate form the most stable species with open chain polyammonium cations, among low molecular weight anions. The N-alkyl substitution does not play negligible role in the stability of these complexes, the species formed by substituted amines being more stable.
De Stefano
Concetta
C
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone 31, Vill. S. Agata, 98166 Messina, Italy.
Foti
Claudia
C
Pettignano
Alberto
A
Sammartano
Silvio
S