Flucytosine Antifungal Drug in Organic-Inorganic Bismuth Chloride Material: Crystal Structure, Optical Properties, Biological Activities, and Computational Insights

In this paper, we report the synthesis and characterization of a new material, (HFlucytosine)₂BiCl₅. The structure studied by single crystal X-ray diffraction reveals one-dimensional (1D) il  [BiCl₅]_n²⁻ chains surrounded by protonated flucytosine antifungal drug (HFlucytosine)⁺. The structure is stabilized by hydrogen bonds and non-covalent interactions. These interactions were assessed using Hirshfeld surface analysis. The optical property of the compound was studied with a focus on the band gap. Theoretical calculations on the electronic structure, band gap, and frontier molecular orbitals were performed using density functional theory (DFT) and time-dependent DFT (TD-DFT) to support our experimental findings. Our results indicate that the energy gap (E_g) and the chemical reactivity descriptors are primarily linked to the ring of the organic cation and the inorganic anion. This highlights the importance of these two components in determining the activity and antioxidant capacity of the molecule. To ascertain the efficacy of these compounds in inhibiting the proliferation of detrimental bacteria, which are prevalent environmental contaminants in the Arab region, an agar disc diffusion assay was performed.