Synthesis and characterization of a hybrid material (C10H28N4) [CoCl4]2 using Hirshfeld surface, vibrational and optical spectroscopy, DFT calculations and biological activities

•A new organic-inorganic hybrid compound (C10H28N4)[CoCl4]2 was successfully synthesized and structurally characterized.•Intermolecular interactions were explored using Hirshfeld surface analysis and RDG approach.•Optical properties of the compound were discussed.•Vibrational bands and structural parameters were investigated by DFT calculations.•Antibacterial activity of compound has been tested by DPPH and ABTS. The preparation and structural characterization of a new complex compound (C10H28N4) [CoCl4]2 (abbreviated BAPCO) were reported. The crystal was grown by the room temperature slow evaporation method and characterized by single crystal X-Ray diffraction. The functional groups present in BAPCO were characterized by several techniques such as FT-IR, UV-Vis absorption and photoluminescence spectroscopy, thermal measurement, Hirshfeld surface analysis and DFT investigation. The title compound crystallizes in the P21/n space group of the monoclinic system with the following cell parameters: a = 18.5765(11) Å, b = 7.1390(4) Å, c = 18.6346(11) Å, β = 110.858(3)°, Z = 4 and V = 2309.3(2) Å3. The structure consists of an alternation along the a-axis of organic layers formed by [C10H28N4]4+cations and inorganic layers built up of isolated tetrahedral [CoCl4]2−. The crystal cohesion is ensured by a network of NH … Cl and CH … Cl hydrogen bonds. Vibrational and optical properties were explored by means of experimental techniques along with DFT and TDDFT calculations. Furthermore, frontier molecular orbital analysis (HOMO-LUMO) was accomplished to understand the chemical stability of BAPCO, and the activation of thermodynamic parameters are calculated. Good agreement was found between theoretical and experimental results. The bioassay results showed that the structure exhibits significant antibacterial activity. [Display omitted]