| Abstract: | The kinetics of the aquation of (H2O)5Cr(O2CCCl3)2+ have been examined at 35–55°C and 1.00M ionic strength with H+] = 0.01?1.00M. The reaction follows the rate equation -d ln Crtotal]/dt = (aH+]?1 + b + cH+])/(1 + dH+]), where Crtotal] is the stoichiometric concentration of the complex. At 45°C a = (1.41 ± 0.03) × 10?7M/s, b = (1.66 ± 0.02) × 10?5 s?1, c = (7.0 ± 0.8) × 10?5M?1·S?1 and d = 2.3 ± 0.3M?1. Two mechanisms consistent with this rate law are discussed, with evidence being presented in favor of an ester hydrolysis mechanism involving steady-state intermediates. Equilibrium and activation parameters were determined. |
