Experimental and theoretical studies on the vibrational spectra and active sites of novel multisubstituted spirocycle isoindolinone-chromene hybrid derivatives

This study investigates the novel compound (Z)-2′-amino-3-(3,5-dichloro-4-hydroxybenzylidene)-6-(diethylamino)-3H-spiro[cyclopenta[b]chromene-9,1′-isoindolin]-3′-one(SPI), a spiroindolenone-chromene, through experimental and theoretical methods. Vibrational modes of SPI were identified using DFT and PED analyses, with calculated spectra matching experimental data. Frontier molecular orbital analysis revealed a HOMO-LUMO gap of 2.934 eV and ESP maps identified electrophilic regions. UV–Vis absorption spectra in various solvents were obtained and validated through TD-DFT simulations, elucidating electron transitions. Molecular docking with MDM2 protein showed strong binding (−10.72 kcal/mol) via hydrogen bonding and π-π stacking. Thermodynamic analyses indicated a transition in dynamics above 700 K, suggesting SPI's potential for drug delivery. This approach lays the groundwork for designing spiro protodrugs with tailored properties, combining spectroscopy, electronic structure theory, and biomolecular modeling.