TY - JOUR
T1 - Polynuclear thiolate complexes in solution. Solution equilibria studies of silver(I) complexes of 3-(dimethylamino)propane-1-thiol and 3-aminopropane-1-thiol and comparative study with 4-mercapto-1-methylpiperidine
AU - González-Duarte, Pilar
AU - Vives, Josep
PY - 1990/12/1
Y1 - 1990/12/1
N2 - The complexation of AgIby the ligands 3-(dimethylamino)propane-1-thiol and 3-aminopropane-1-thiol has been studied first in strong acidic solutions and then at increasing pH values, up to pH ≤ 8, at 25 °C in 0.1 mol dm-3NaNO3(10% v/v MeOH). The extended-variation method and other graphical methods based on the 'core + links' hypothesis have been used and give results in accord with the final equilibrium model obtained by means of the program SUPERQUAD. Species [Agp(AH)q]p+, AH denoting the monoprotonated ligand, in a strong acidic medium have the same stoicheiometric coefficients and comparable formation constants with both ligands; p,q values are 6,3; 6,4; 8,6; 7,6; 10,9; and 12,12. The species 5,6 is already present at low pH with H2N(CH2)3SH. More basic solutions contain species with p,q values 5,6; 4,6; and 1,3 in the case of Me2N(CH2)3SH and 5,6; 5,7; 4,6; 2,4; and 1,3 in that of H2N(CH2)3SH. These results together with those obtained with 4-mercapto-1-methylpiperidine indicate that the species existing in a strong acidic medium are independent of the aliphatic chain of the ligand, whereas at higher pH values the nuclearity and the number of species present depend on the nature of the γ-mercaptoamine.
AB - The complexation of AgIby the ligands 3-(dimethylamino)propane-1-thiol and 3-aminopropane-1-thiol has been studied first in strong acidic solutions and then at increasing pH values, up to pH ≤ 8, at 25 °C in 0.1 mol dm-3NaNO3(10% v/v MeOH). The extended-variation method and other graphical methods based on the 'core + links' hypothesis have been used and give results in accord with the final equilibrium model obtained by means of the program SUPERQUAD. Species [Agp(AH)q]p+, AH denoting the monoprotonated ligand, in a strong acidic medium have the same stoicheiometric coefficients and comparable formation constants with both ligands; p,q values are 6,3; 6,4; 8,6; 7,6; 10,9; and 12,12. The species 5,6 is already present at low pH with H2N(CH2)3SH. More basic solutions contain species with p,q values 5,6; 4,6; and 1,3 in the case of Me2N(CH2)3SH and 5,6; 5,7; 4,6; 2,4; and 1,3 in that of H2N(CH2)3SH. These results together with those obtained with 4-mercapto-1-methylpiperidine indicate that the species existing in a strong acidic medium are independent of the aliphatic chain of the ligand, whereas at higher pH values the nuclearity and the number of species present depend on the nature of the γ-mercaptoamine.
U2 - 10.1039/DT9900002483
DO - 10.1039/DT9900002483
M3 - Article
SP - 2483
EP - 2489
IS - 8
ER -