RELATIONSHIPS BETWEEN ET POLARITY AND COMPOSITION IN BINARY SOLVENT MIXTURES

A new equation for facile computation of E(T)(30) values of binary solvent mixtures from their composition (mole fraction, volume fraction, molality or molarity) is derived. The equation is based on one parameter which takes into account the preferential solvation of the E(T) indicator by the solvents of the mixture. The equation has been successfully applied to 52 binary solvents. The results show that the studied binary solvents show four different behaviours which can be explained in terms of solvent-solvent interactions. The proposed equation allows a simple definition of the solvent polarity as a function of composition.