= 1-(2-pyrimidyl)piperazine). Under excitation light, all compounds exhibit bright blue emission with a maximum photoluminescence quantum yield (PLQY) of 47.82%, owing to the enhanced quantum and dielectric confinement offered by the insulating organic matrix. The luminescence originates from the synergistic interaction of the organic cations and inorganic tetrahedra. These halides exhibit excellent optical properties and thermal stability that are necessary for lighting and display applications.