| Popis: |
Rate constants are reported for the reaction between bromide ions and the complex ion [PdCl(tedien)]+(tedien =NNN″N″-tetraethyldiethylenetriamine) in aqueous solution containing various concentrations of bromide salts. The first-order rate constant for the unimolecular substitution reaction decreases with increase in salt concentration, the effect being more marked through the series NBun4+ > NPr4+ > NEt4+ > NMe4+ > K+≃ Na+. Comparison of rate data and solubilities of the complex chloride salt in 1.0 mol dm –3 KCl, [NEt4]Cl, and [NBu4]Cl indicates that the dominant salt effect operates on the transition state, where hydration and ion-size effects lead to a marked destabilisation. |
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