Pressure Enhancement of Charge-Transfer Complexing of 1-Methyl-3-(carbomethoxy)pyridinium Cation and 8-Chlorotheophyllinate Anion Aqueous Solution

Article abstract of DOI:10.1021/j150613a007

Values have been obtained for the association constant of the acceptor 1-methyl-3-(carbomethoxy)pyridinium cation with the donor 8-chlorotheophyllinate anion in aqueous solution at pH 7.0, I=0.5, T=25 deg C, at pressures from 0.1 to 209.5 MPa.From these data the apparent volume change on association is estimated to be ΔV=-4.0+/-0.5 cm³mol^-1, and the increment in compressibility is Δ_κ=0.0 Pa^-1.No significant change in the increment in the extinction coefficient, Δε, was observed.The results are interpreted in terms of the volume changes to be expected on association due ion pairing, charge transfer, and the approach of aromatic rings in water.