Single-crystal growth, crystal structure, and molecular dynamics of organic-inorganic [NH₃(CH₂)₂NH₃]CuBr₄

As part of obtaining excellent properties that can be used as lead-free hybrid solar cells, the crystal growth, crystal structure, phase transition temperature, and thermal properties for [NH₃(CH₂)₂NH₃]CuBr₄ were discussed. The crystal structure at 300 K was determined to be monoclinic by single-crystal X-ray diffraction (XRD) analysis. The phase transition temperatures were determined to be 447 and 473 K, and the results were consistent with the powder XRD patterns. Thermogravimetric analysis revealed thermal stability up to ~ 460 K. The continuous changes in the ¹H and ¹³C chemical shifts and ¹⁴N static resonance frequency with increasing temperature are related to variations in the local environment and coordination geometry. The significant differences in activation energies obtained from the ¹H and ¹³C spin-lattice relaxation times (t_1ρ) at low and high temperatures were discussed. The activation energy results suggested that the energy barrier at low temperatures was related to the reorientation of the NH₃ and CH₂ groups around the three-fold symmetry axis, and the energy barrier at high temperatures was related to the reorientation of the [NH₃(CH₂)₂NH₃] cation. These physical properties will be provide important insights or potential applications of this crystal.Please check and confirm that the corresponding author and their respective corresponding affiliation have been correctly identified and amend if necessary.OK !