Charge transfer complexes of picolines with σ- and π-acceptors

In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano parabenzoquinone (π-acceptor) and (I2) Iodine (σ-acceptor) have been investigated spectrophotometrically in three different solvents (CCl4, CHCl3 and CH2Cl2) at six different temperatures. The formation constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters were calculated by Van't Hoff equation. The ΔH°, ΔG° and ΔS° values are all negative implying that the formation of studied complexes is exothermic in nature.