Spectrophotometric and Spectroscopic Studies of Charge Transfer Complexes of M-Nitroaniline as an Electron Donor with Picric Acid as an Electron Acceptor in Different Polar Solvents

Charge transfer complexes of picric acid, with m-nitroaniline, were investigated by spectrophotometric method in three different organic solvents viz-acetone, ethanol, and methanol. The data are discussed in terms of association constant, (K_CT) and molar extinction coefficient (ε_CT), standard free energy (ΔG^°), oscillator strength (ƒ), and transition dipole moment (μ_EN) were calculated. The spectrum obtained form the complex of picric acid and m-nitroaniline shows absorption bands at 450 nm for methanol, 445 nm for ethanol and 440 nm for acetone. The results reveal that the interaction between the donor and acceptor is due to π-π* transitions. The stiochiometry of the complexes was found to be in the ratio of 1:1 by straight line method. The influences of used solvents such as acetone, ethanol, and methanol, on spectroscopic parameters were investigated. The ionization potential (I_D) of the donor was also determined.