Bromination of Organic Spacer Impacts on the Structural Arrangement, Phase Transitions, and Optical and Electrical Properties of a Hybrid Halide Compound:[(Ch3)3n(ch2)3br]2pdbr4

Understanding the structure and arrangement of organic inorganic hybrid metal halides and their contribution to physical properties remains a challenging topic. In particular, materials involving d(8) metal halides incorporating organo-halogen components are still largely unexplored. In this study, we have used precise reagents to design and synthesize a low dimensional semiconductor material, [(CH3)(3)N(CH2)(3)Br](2)PdBr4. Crystals were prepared through slow evaporation. Through the reactions of (3-bromopropyl)trimethylammonium bromide with PdBr2 in an aqueous HBr solution, we successfully obtained a 0D organic-inorganic hybrid material, [(CH3)(3)N(CH2)(3)Br](2)PdBr4. This compound exhibits two reversible phase transitions, at 363 K and 393 K, assigned to an order/disorder change and a rare congruent melting. These transitions are confirmed through DSC analysis, temperature dependent Raman studies and electrical measurements. The crystals remained stable up to 520 K. Furthermore, we measured the UV-visible absorption spectrum of the polycrystalline sample to estimate the band gap, which was found to be approximately 2 eV. The halogen atom in the organic spacer has a considerable impact on the structure, high-temperature phase transition, and semiconducting characteristics, as revealed in this work.