Investigation on the structural, optical, photoluminescence and electric properties of a semiconductor material [Br(CH2)2N(CH3)3]2SnBr6.

A new low-dimensional hybrid tin(iv) halides, [Br(CH2)2N(CH3)3]2SnBr6, was synthesized via slow evaporation from acidic aqueous solution under ambient conditions. Single-crystal X-ray diffraction reveals that the compound crystallizes in the orthorhombic space group Pbca, featuring discrete [SnBr6]2- octahedra spatially isolated and electrostatically stabilized by [Br(CH2)2N(CH3)3]+ cations. The crystal packing is reinforced through a network of C-H⋯Br hydrogen bonds and halogen···halogen contacts, forming a 0D supramolecular framework. Infrared spectroscopy confirms the existence of characteristic vibrational modes from organic molecule. Furthermore, the thermal behavior studied by (TGA-DSC) indicates good thermal stability up to 430 K. Optical absorption studies yield a direct optical band gap of 3 eV and an indirect gap of 2.54 eV, consistent with semiconducting behavior. Under UV excitation, the compound exhibits blue photoluminescence centered at 434 nm, attributed to excitonic recombination confined within the [SnBr6]2- units. Impedance spectroscopy further reveals thermally activated conduction, following non-overlapping small polaron tunneling and correlated barrier hopping models. These findings suggest that [Br(CH2)2N(CH3)3]2SnBr6 is a structurally robust, lead-free semiconductor with blue emission, making it a promising candidate for environmentally benign optoelectronic devices such as LEDs and photonic components.