Study on crystal structure, thermal property, and nuclear magnetic resonance spin-lattice relaxation times of organic-inorganic hybrid [NH 3 (CH 2 ) 6 NH 3 ]ZnCl 4

Abstract Organic-inorganic hybrid compounds have recently gained significant attention in recent years due to their diverse applications. Herein, [NH3(CH2)6NH3]ZnCl4 crystals were grown, and their triclinic structure, phase transition temperature (TC = 408 K), and high thermal stability (Td =584 K) was determined using X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetry measurements. By analyzing the chemical in response to temperature changes, we observed that the coordination geometry around 1H and 13C were highly symmetric below TC, whereas their symmetry was lowered above TC. The change of N‒H∙∙∙Cl hydrogen bond from XRD results and the change of 14N NMR chemical shifts was due to the changes to the coordination geometry of Cl around Zn2+ in the ZnCl4 anion. The activation energy of 1H was three times greater than that of 13C, and this result indicates that the energy transfer of 13C was easier than those of 1H. We compared the results for [NH3(CH2)nNH3]ZnCl4 (n=6) studied here with those for n=2, 3, 4, and 5 obtained from previous studies. The characteristics of the length of CH2 and even–odd number of carbons in the methylene chain are expected to be used for potential applications in the near future.