Spectrophotometric study on the charge transfer reaction between 2-amino-4-methylpyridine with chloranilic acid in polar solvents

Charge transfer (CT) complexes formed between 2-amino-4-methylpyridine as electron donor, chloranilic acid as electron acceptor was investigated spectrophotometrically in acetonitrile (AN), methanol (MeOH) and binary mixture of acetonitrile 50% + methanol 50% (MeOH-AN). Minimum-maximum absorbance method has been used for estimating the formation constants of the CT reactions (K-CT). Job's method of continuous variation and photometric titration studies were used to detect the stoichiometric ratios of the formed complexes, and they showed that 1:1 complexes were produced. The molar extinction coefficient (e), oscillator strength (f), dipole moment (l), CT energy (E-CT), ionisation potential (I-P) and the dissociation energy (W) of the formed complexes were estimated; they reached acceptable values suggesting the stability of the formed CT complexes. The solid CT complexes were synthesised and characterised by elemental analyses, H-1 NMR and FTIR spectroscopies where the formed complexes included proton and electron transfer.