Synthesis, crystal structure, antibacterial properties, and DFT studies of a new organic-inorganic hybrid [4NO2BzT(4Me)PP]2[CuBr4]

In this paper, a new organic-inorganic hybrid crystal 1-(4 '-nitrobenzyltris(4-methylphenyl)phosphonium) tetrabromocuprate(II) [4NO2BzT(4Me)PP]2[CuBr4](1) was synthesized and characterized by X-ray diffraction, IR spectrum, scanning electron microscopy, and ultraviolet-visible diffuse reflectance spectrum. The complex crystallized in the monoclinic space group C2/c. The [4NO2BzT(4Me)PP]+ cations and the [CuBr4]2- anions were connected by C - H<middle dot><middle dot><middle dot>Br hydrogen bonding. DFT calculations estimate the intermolecular energy, the energy gap between the HOMO and LUMO orbitals, and more. The low energy gap explained the charge transfer interactions occurring between the [4NO2BzT(4Me)PP]+ cations and the [CuBr4]2- anions. Moreover, the complex exhibited superior antibacterial activity against Escherichia coli and Staphylococcus aureus.