A comprehensive study of the crystal structure and dynamics of [N(C₃H₇)₄]₂Cd₂Cl₆

Single crystals of the organic-inorganic hybrid compound [N(C₃H₇)₄]₂Cd₂Cl₆ were synthesized by an aqueous solution method, and their structural and dynamic properties were systematically investigated. Thermal analyses revealed phase transitions at 321 K (T_C1) and 445 K (T_C2), followed by melting at 476 K. Single-crystal X-ray diffraction indicated that the compound crystallizes in a triclinic system with space group P[Formula: see text], showing variations in lattice parameters across T_C1 while maintaining the same symmetry. On the other hand, whereas the ¹H, ¹³C, and ¹⁴N MAS NMR chemical shifts of the [N(C₃H₇)₄] cations showed little variation near T_C1, the ¹¹³Cd MAS NMR spectra of the Cd₂Cl₆ anions revealed a clear change, with two Cd sites (Cd(1) and Cd(2)) merging into a single site. This agrees well with the SCXRD results, indicating that the phase transition at T_C1 arises primarily from an order-disorder transition of the Cd₂Cl₆ anions rather than the [N(C₃H₇)₄] cations. In addition, temperature-dependent line narrowing in the¹H, ¹³C, ¹⁴N, and ¹¹³Cd NMR spectra reflects enhanced molecular dynamics at elevated temperatures. These results provide insights into the phase behavior and stability of [N(C₃H₇)₄]₂Cd₂Cl₆, highlighting its potential relevance for future functional applications.