Photoluminescence and switchable dielectric properties of (R/S-3-hydroxypiperidinium)MnCl3 with high-temperature phase transitions

Manganese(II)-based hybrid materials with high phase transition temperatures have attracted considerable interest owing to their promising applications in the field of optics. In this work, we report a pair of manganese(II)-based chiral organic-inorganic hybrid compounds, (R/S-3-hydroxypiperidinium)MnCl₃, both of which crystallize in the non-centrosymmetric P2₁2₁2₁ space group at room temperature. The chiral enantiomeric nature of these compounds was confirmed through vibrational circular dichroism (VCD) spectroscopy. They exhibited a reversible solid-state phase transition at 434 K, accompanied by prominent dielectric switching behavior. Notably, both enantiomers exhibit intense red photoluminescence under ultraviolet excitation, attributed to the d-d transition of Mn²⁺ ions. These findings highlight the potential of chiral hybrid materials with high-temperature phase transitions for the development of advanced multifunctional optoelectronic materials.