Charge Transfer Complexes of 1-Cyclohexylpiperazine as Donor with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 2,3,5,6-Tetra chloro-p-benzoquinone as Acceptors: A Comparative Studies of Spectroscopic, Thermodynamic and DFT Analysis

Novel 1-cyclohexylpiperazine charge transfer compounds, acting as donors, were investigated in conjunction with the π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 2,3,5,6-tetrachloro-p-benzoquinone (CHL) through spectrophotometric analysis at room temperature in acetonitrile. The Benesi-Hildebrand equation was applied to determine the molar extinction coefficient (ε) and stability constant (KCT) for both charge transfer (CT) complexes, each exhibiting a 1:1 molar composition. The infrared (IR) spectroscopy confirmed the presence of CT complexes and these complexes were further evaluated for their pharmacological potential in DNA binding studies, revealing their interaction with DNA through intercalation. The density functional theory (DFT) analysis provided insights into bond lengths, bond angles, Mulliken atomic charges, molecular electrostatic potential (MEP) maps and the highest occupied molecular orbital to the lowest unoccupied molecular orbital (HOMO-LUMO) characteristics of the CT complexes.