Preparation of Fe(II) − 6-chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H-1-benzopyran complex for analytical, biological & computational studies.

[Display omitted] • Spectrophotometric trace determination. • 6-Chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H-benzopyran (CHMTB) • Fe(II)- (CHMTB)complex. • DFT Study of Fe(II)-CHMTB complex. • Antibacterial activity study Fe (II)-CHMTB complex. An easy, rapid, sensitive and selective spectrophotometric method which shows maximum absorbance at 433 nm to detect micro amount of Fe(II) with 6-chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H benzopyran(CHMTB) has been developed which form a stable dark brownish complex in an acidic environment which is extractable in dichloromethane (DCM). The complex showed molar absorptivity coefficient and sandell'ssensitivity 2.335 x 104 l mol-1and 0.0023 µg cm−2 respectively.The correlation value and detection limit for this method is 0.9998 and 0.0893 µg ml−1 respectively. Various cations and anions/complexing agents had no effect on the detection of divalent iron.The DFT/B3LYP/6-31G(d,p) method is a commonly used computational approach used for studying molecular properties and to calculate energy gaps for complex and ligand which are foundto be 0.0767 eV and 0.1380 eV respectively. Global reactivity descriptors provide valuable information about the reactivity and stability of molecules. Molecular Electrostatic Potential (MEP) analysis is a useful tool for identifying potential sites for nucleophilic or electrophilic attacks on chemical structures. The complex interaction with anti-cancer, antibacterial, and antifungal agents had been thoroughly studied along with the selectivity of the method by its detection in presense of other metal ions. [ABSTRACT FROM AUTHOR]