A hybrid molecular rotor crystal with dielectric relaxation and thermochromic luminescence

Abstract

Herein, we reported a hybrid crystals, [C3-Mim][PbBr3] (1) where C3-Mim+ = 1-propyl-3-methylimidazolium, this compound shows two steps solid-solid phase transition at 256 and 359 K, respectively. The first phase transition is related to the strong thermal vibrations of the crystal lattice, and the alkyl chain rotation motion on a single axis of organic cations can be observed from the temperature dependent crystal structure. The second step phase transition were proved by temperature dependent powder X-ray diffraction and accompanied by remarkable dielectric relaxation. In addition, the temperature-dependent photoluminescent indicated two emission bands from organic and inorganic component have different sensitivity to temperature, leading to 1 showing photoluminescent thermochromism, which may have potential application in the thermosensitive devices.