The compound 3′‐(1‐benzyl‐5‐methyl‐1H‐1,2,3‐triazole‐4‐carbonyl)‐1′‐methyl‐4′‐(3‐nitrophenyl)‐2H‐spiro[acenaphthylene‐1,2′‐pyrrolidin]‐2‐one [BTNANP] was synthesized and characterized by (FT‐IR/FT‐Raman), NMR (1H and 13C), UV‐Visible, Fluorescence and XRD studies. The molecular geometry was optimized using density functional theory (DFT/B3LYP) method with 6–311G (d,p) basis set in the ground state and compared with the experimental data. The entire vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED) by VEDA 4 programme. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analysed using the Natural Bond Orbital (NBO) analysis. It was also confirmed by the assignments of UV‐Vis spectrum. The fluorescence spectrum confirms that the title compound is a red‐light emitting material. In addition, NLO, MEP, Mulliken atomic charges, thermodynamic properties, HOMO and LUMO energy gap were theoretically predicted. The global chemical reactivity descriptors were calculated for BTNANP and used to predict their relative stability and reactivity. The antimicrobial activity of the compound was also tested against the selected bacterial and fungal pathogens. The molecular docking studies concede that the title compound may exhibit inhibition activity against topoisomerase II and lanosterol 14 α‐demethylase.