Kinetics and Mechanism for Reaction between Ammine- and Haloamminegold(III) Complexes and Thiocyanate. Competitive Electron Transfer and Substitution
The reactions in acidic aqueous solution between thiocyanate and each of the gold(II1) complexes Au(NH,)?+, rrans-Au- (NH,)zC12t, and rrans-A~(NH,)~Br~+ have been studied by use of potentiometric pH measurements and sequential-mixing stopped-flow spectrophotometry. The reactions give a common gold(1) product whereas the rate-controlling steps are different. The reaction between Au(NH,)?+ and thiocThe reactions in acidic aqueous solution between thiocyanate and each of the gold(III) complexes Au(NH3)43+, trans-Au(NH3)2C12+, and trans-Au(NH3)2Br2+ have been studied by use of potentiometric pH measurements and sequential-mixing stopped-flow spectrophotometry. The reactions give a common gold(I) product whereas the rate-controlling steps are different. The reaction between Au(NH3)43+ and thioc