THERMODYNAMICS OF PROTON DISSOCIATION OF ACRIDINIUM ION IN AQUEOUS-SOLUTION

Standard thermodynamic function changes (Delta G(theta)(0), Delta H-th eta(0), Delta S-theta(0) and Delta C-p theta(0)) are reported for prot on dissociation of acridinium cation in aqueous solution. These values have been determined from a series of precise and accurate acid equil ibrium constants, K,. The equilibrium constants have been obtained spe ctrophotometrically over a range of temperatures from 2 to 66 degrees C at several ionic strengths (I = 0.005, 0.007, 0.01, 0.05 and 0.25 M) . Although the ionic strength does not affect in general the Gibbs fre e-energy values, the results suggest a possible influence on entropy a nd enthalpy changes. (C) 1998 Elsevier Science B.V. All rights reserve d.