A benzopyran-based optical sensor for selective trace detection of Pd(II): Analytical and computational investigation

3-Hydroxy-2-phenyl-4H-chromen-4-one (HPC), a chromogenic reagent acting as an optical sensor for the metal to be determined and having a sensitive impact on the spectrophotometric Pd (II) determination in the organic phase, has been studied in the present investigation. The ideal conditions for complexation were depicted by the various statistical evidences for instance standard deviation (SD = ± 0.00184), Sandell’s sensitivity (S = 0.0055 μg cm-2), detection limit (LOD = 0.1122 μg mL-1) and regression coefficient (r = 0.9975). The attenuation coefficient of Pd (II)-HPC complex was 1.9159×104 L mol-1 cm-1 calculated at a wavelength range of 417-432 nm of the resulting stable binary yellow complex. Analytical findings support a square planar geometry of the investigated coordination complex. The theoretical studies for instance Density Functional Theory (DFT) have been conducted in order to enhance our comprehension about the complex's molecular geometry and its structural attributes. DFT, has a strong correlation with the analytical findings, proving that the studied complex behaves as a strong bioactive agent. The investigated complex was indeed subjected to antimicrobial and antioxidant studies, results of which reflected that the formed complex has a strong potential to act as a strong antimicrobial and a radical scavenging agent compared to ligand alone. Along with, the formed complex has been employed on commercial samples and has come out with remarkable sensitivity, selectivity, accuracy and precision, under set conditions of the procedure.