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.

The thermal- and mechanical-properties and optical transparency of the copoly(amide imide) films with different BPA monomer contents were investigated.

Powder X-ray diffraction patterns of [NH3(CH2)6NH3]CuCl4 at different temperatures.

Although PEI/PAA multilayers are insulators, when used as a p-type buffer layer in organic photodetector, they suppressed the leakage current and also provided a high photocurrent due to the light-assisted tunneling effect.