Stability of diammine and chloroammine gold(I) complexes in aqueous solution
作者:I. V. Mironov
DOI:10.1134/s003602360706023x
日期:2007.6
The substitution equilibria AuCl2- + iNH(4)(+)= Au(NH3)(i)Cl2 - i + iCl(-) + iH(+), beta(i) (*). were studied pH-metrically at 25 degrees C and I = 1 mol/L (NaCl) in aqueous solution. It was found that log beta(*)(1)= -5.10 +/- 0.15 and log beta(*)(2) = -10.25 +/- 0.10. For equilibrium AuNH3Clsolid = AuNH3Cl, log K-s = -3.1 +/- 0.3. Taking into account the protonation constants of ammonia (logK(H) = 9.40), the obtained results show that for equilibria AuCl2- + iNH(3) = Au(NH3)(i)Cl2 - i + iCl(-), log beta(1) = 4.3 +/- 0.2, and log beta(2) = 8.55 +/- 0.15. The standard potentials E-1/0(0) of AuNH3Cl0 and Au(NH3)(2)(+) species are equal to 0.90 +/- 0.02 and 0.64 +/- 0.01 V, respectively.