Synthesis of charge transfer complex of chloranilic acid as acceptor with p-nitroaniline as donor: Crystallographic, UV-visible spectrophotometric and antimicrobial studies

The charge transfer interaction between p-nitroaniline (PNA) and chloranilic (CAA) acid was studied spectrophotometrically in methanol at different temperatures within the range 298-328 K. This experimental work explores the nature of charge-transfer interactions that play a significant role in chemistry and biology. Structure of synthesized charge transfer (CT) complex was investigated by different technique such as X-ray crystallography, FTIR, (HNMR)-H-1, UV-visible spectroscopy, XRD and TGA-DTA, which indicates the presence of N+-H <= O- bond between donor and acceptor moieties. Spectrophotometric studies of CT complexes were carried out in methanol at different temperatures to estimate thermodynamic parameters such as formation constant (K-CT), molar absorptivity (epsilon(CT)), free energy change (Delta G), enthalpy change (Delta H), resonance energy (R-N), oscillator strength (f), transition dipole moment (mu(EN)) and interaction energy (E-CT) were also calculated. The effect of temperatures on all the parameters was studied in methanol. 1:1 stoichiometric of CT-complex was ascertained by Benesi-Hildebrand plots giving straight line, which are good agreement with other analysis. Synthesized CT complex was screened for its antimicrobial activity such as antibacterial activity against two gram positive bacteria, Staphylococcus aureus and bacillus subtilis and two gram negative bacteria Escherichia coli and pseudomonas aeruginosa, and antifungal activity against fungi Fusarium oxysporum, and Aspergillus flavus. (C) 2017 Elsevier B.V. All rights reserved.