An O-17, F-19, and Al-27 NMR study of fluoroaluminate complexes (AlFn(H2O)(6-n), n = 0, 1, and 2) in aqueous solution supports the idea that for each substitution of a bound water molecule by a fluoride anion, the exchange rate of bound water with free water increases by about 2 orders of magnitude. New rate coefficients for exchange of inner-sphere water molecules in AlF(H2O)(5)(2+) are k(ex)(298) = 230(+/- 20) s(-1), DeltaH(double dagger) = 65(+/-3) kJ mol(-1), and DeltaS(double dagger) = 19(+/- 10) J mol(-1) K-1. The corresponding new values for the AlF2(H2O)(4)(+) complex are: k(ex)(298)= 17 100(+/- 500) s(-1), DeltaH(double dagger) = 66(+/-2) kJ mol(-1), and DeltaS(double dagger) = 57(+/-8) J mol(-1) K-1. When these new results are combined with those of our previous study,4 We find no dependence of the solvent exchange rate, in either AlF(H2O)(5)(2+) or AlF2-(H2O)(4)(+), on the concentration of fluoride or protons over the range of SigmaF = 0.06-0.50 M and [H+] = 0.01-0.44 M. A paramagnetic shift of Al-27 resonances results from addition of Mn(ll) to the aqueous solution as a relaxation agent for bulk waters. This shift allows resolution of the AlFn(H2O)(6-n)((3-n)+) species in Al-27 NMR spectra and comparison of the speciation determined via thermodynamic calculations with that determined by Al-27, F-19, and O-17 NMR.