Spectrophotometric trace determination of Fe(II) with 5,7-dibromo-8-hydroxyquinoline and investigating the spectral, antimicrobial, anticancer properties and DFT study of iron complexes

Abstract

A simple, selective and versatile spectrophotometric technique has been developed for determination of iron in novel complex of iron with 5,7-Dibromo-8-hydroxyquinoline in a basic medium. The green-colored complex was extractable in chloroform within the pH range of 8.95–8.99 with maximum intensity of color in the wavelength range of 429–439 nm. Analytical techniques confirmed the complex stoichiometry of 1:2 [Fe(II)-DBHQ]. Several parameters were also calculated like Sandell^’s sensitivity (0.001953 µg cm⁻²), molar absorptivity coefficient (2.849 × 10⁴ L mol⁻¹ cm⁻²), standard deviation of reproducibility (± 0.001048/0.205%), detection limit (0.14 µg/ml) and regression coefficient (0.9497). These parametric values showed higher adaptability, cost-effectiveness and higher sensitivity of the proposed method of complex determination as compared to already reported methods. Computational chemistry calculations were studied using DFT, and global reactivity descriptors such as electronegativity, softness, hardness, electron affinity, ionization potential and electrophilicity were estimated with HOMO and LUMO energies. Using MEP analysis possible targets for nucleophilic or electrophilic attacks on the chemical structures of the complex were identified. In vitro anticancer and antimicrobial activity of the complex was further determined, and the complex showed antineoplastic as well as antimicrobial potency, hence showed the novel complex compatibility in antimicrobial and anticancer applications like therapeutic agents and metal-based drugs.