Effect of Methylene Chain Length on the Thermodynamic Properties, Ferroelastic Properties, and Molecular Dynamics of the Perovskite-type Layer Crystal [NH₃(CH₂)_nNH₃]MnCl₄ (n = 2, 3, and 4)

Abstract

The structures and phase transitions of [NH 3 (CH 2 ) n NH 3 ]MnCl 4 ( n = 2, 3, and 4) crystals were confirmed through X-ray diffraction and differential scanning calorimetry (DSC) experiments. Thermodynamic properties, ferroelastic properties, and molecular dynamics of three crystals were studied as a function of the number ( n ) of CH 2 groups in the alkylene chains. The loss in molecular weight due to a decrease in n marked the onset of the partial thermal decomposition. The thermal decomposition temperature, T d , increased with increasing length of the CH 2 chain. While the ferroelastic twin domain walls for n = 2 and 4 were in the same direction at all temperatures, the domain walls for n = 3 were rotated by 45°, and the direction of extinction in phase II was rotated by 45° with respect to phases I and III. The 1 H and 13 C MAS NMR spectra of the three crystals were recorded as a function of temperature. With increasing length of the CH 2 chain, the 1 H spin relaxation time decreased, indicating that molecular motions were activated. These results provide insights into the thermodynamic properties and structural dynamics of the [NH 3 (CH 2 ) n NH 3 ]MnCl 4 crystals and are expected to facilitate their potential applications.

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

“…The 14 N static NMR spectrum of [NH 3 (CH 2 ) 6 NH 3 ]ZnCl 4 single crystal was obtained in the temperature range of 180-420 K (Fig. 6).…”

“…6). The 14 N chemical shift range exhibited a signi cantly wider span compared to the 1 H chemical shift range, making it valuable for determining the surrounding environment of 14 N. In this study, the external magnetic eld was measured in an arbitrary direction of the single crystal. Considering the spin number of 14 N as I=1, the NMR spectrum predicts two resonance lines due to the quadrupole interaction.…”

“…Considering the spin number of 14 N as I=1, the NMR spectrum predicts two resonance lines due to the quadrupole interaction. 41 However, due to the very low Larmor frequency of 28.90 MHz for obtaining the 14…”

“…In this study, organic-inorganic hybrid [NH 3 (CH 2 ) 6 NH 3 ]ZnCl 4 single crystals replacing with eco-friendly were grown using the aqueous solution method, and their crystal structures, phase transition temperatures (T C ), and thermal properties were studied. The effect of temperature on coordination geometry, which can provide valuable insights into the physical and chemical properties of compounds, was discussed based on information obtained from 1 H, 13 C, and 14 N nuclear magnetic resonance (NMR) chemical shifts. The energy transfer was investigated by employing the spin-lattice relaxation time (T 1ρ ).…”

A ferroelastic molecular rotator [(Me2N(CH2)2NH3)(18-crown-6)]triflate with dual dielectric switches

“…Although the ferroelastic strain-stress hysteresis is one of the distinctive features of ferroelastic materials, the polarizing microscope as a supplement could be used to observe ferroelastic domain patterns based on the birefringence characteristics of ferroelastics in different orientations, when the ferroelastic hysteresis loop is hard to detect. 24,[47][48][49][50][51][52][53][54] As shown in Fig. 5(a), the distinct striplike ferroelastic domains of compound 3 are recorded under the polarizing microscope at 278 K, which are significantly independent of the surface topography of the compound.…”