Solvent effect on the charge-transfer complex of chloranil with pyrene

Abstract

The spectrophotometric and thermodynamic properties of the charge-transfer (CT) complex of chloranil with pyrene have been studied in different solvents, such as n-hexane, cyclohexane, n-heptane, carbon tetrachloride, chloroform, dichloromethane and benzene. The transition dipole moment ( D) and oscillator strength ( f) of the CT absorption band in this complex are shown to increase with its heat of formation ( -Δ H°) in different solvents. The change in the thermodynamic as well as spectrophotometric properties of the chloranil-pyrene complex in different solvents is assumed to be due to the solvent interaction with chloranil and an attempt has been made to calculate these properties of the complex free from the influence of the solvent.