Spectroscopic studies of multiple charge transfer complexes of p-toluidine with π-acceptor picric acid in different polar solvents

Abstract

The charge transfer complexes of the donor p-toluidine with π-acceptor picric acid have been studied spectrophotometrically in various solvents such as acetone, ethanol, and methanol at room temperature using absorption spectrophotometer. The results indicate that formation of CTC in less polar solvent is high. The stoichiometry of the complex was found to be 1: 1 ratio by straight line method between donor and acceptor with maximum absorption bands. The data are discussed in terms of formation constant (KCT), molar extinction coefficient (ɛCT), standard free energy (ΔG°), oscillator strength (f), transition dipole moment (μEN), resonance energy (RN) and ionization potential (ID). The results indicate that the formation constant (KCT) for the complex were shown to be dependent upon the nature of electron acceptor, donor and polarity of solvents which were used.