In this paper, we report on the chemical preparation, crystal details, vibrational, optical, and thermal behavior, and antibacterial activity of a new non-centrosymmetric compound: 4-tert-butyl-pyridinium tetrachloridocuprate. X-ray diffraction analysis shows that the structure has a 3D network made up of C–H…Cl and N–H…Cl H-bonds, and [CuCl₄]²⁻ anions have a shape halfway between a tetrahedron and a square planar structure in this compound’s monoclinic system. Hirshfeld surface analysis was used to explain the nature and extent of intermolecular interactions, highlighting the importance of the H-bonds and the C–H⋯π interactions in the structure’s stabilization. Additionally, SEM/EDX experiments were conducted. The powder X-ray diffraction investigation at room temperature validated the material purity. Moreover, the different functional groups were identified using FT-IR spectroscopy. In addition, the optical properties were investigated using UV-Vis absorption. The thermal stability of (C₉H₁₄N)₂[CuCl₄] was performed by TGA-DTA. The bactericidal potency of the title compound was surveyed.