Abstract
In the present study, structural and chemical properties of two flavonoid compounds, Apigenin and Kaempferol are examined using density functional theory (DFT). The structural and electronic properties of Apigenin and Kaempferol are simulated using geometric optimization, vibrational, and UV-Vis spectra analysis. The computed electronic spectra and vibrational spectra of Apigenin and Kaempferol show excellent correlation with experimental spectra. Interaction energy analysis reveals that non-covalent interactions exist between phytochemicals (Apigenin and Kaempferol) and toxic gases (NH3 and HCOOH). The moderate equilibrium constant (Kint) values (calculated from IR data) and NCI analysis also support non-covalent type interaction between complexes. Maximum value of Kint for Kaempferol-HCOOH complex indicates that Kaempferol phytochemical exhibits the highest sensing ability towards HCOOH. Moreover, FMO results also indicate that the highest decrease in HOMOLUMO gap is observed for Kaempferol-HCOOH complex. Moreover, the UV-Vis absorption study reveals that these flavonoids can act as chemosensors for the selective detection of formic acid over ammonia. We strongly believe that current study will provide guidance to researchers to explore the potential application of natural products in sensing of toxic gases.