A comparative study of structural, spectral, solvatochromic, and binding properties of 2,4-dinitrophenylhydrazones: An experimental and computational approach

A comparative study of structural, spectral, solvatochromic, and binding properties of regioisomeric o-/m-/p-chlorobenzaldehyde 2,4-dinitrophenylhydrazones and their phenylhydrazones and chlorine-unsubstituted analogues is presented. The effects of chloro and nitro substituents on their molecular-electronic structure, vibrational modes, chemical shift, UV-visible absorption characteristics, and physiological properties are evaluated using spectroscopic methods and DFT calculations. Chlorobenzaldehyde 2,4-Dinitrophenylhydrazones exhibit enhanced polarizability and hyperpolarizability coefficients, lower band gaps, and decreased global hardness, whereas the chlorine-unsubstituted phenylhydrazone displays better binding affinity with the receptor protein. Experimental and TD-DFT simulated absorption spectra, recorded in various solvents, reveal a substantial influence of substituents, position, and solvent medium on their absorption characteristics. This comprehensive study provides valuable insights into the qualitative structure-property relationship of the regioisomers, informing their speculated applications in sensors, optical switches, and drug discovery.