Thermal Energy-Driven Solid-State Molecular Rotation Monitored by Real-Time Emissive Color Switching

Abstract

Inspired by nature's molecular machines, the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored. Here we report a unique example of a thermal energy-driven stimuliresponsive solid-state molecular rotor, which is featuring with an o-carborane moiety as a rotor that directly transduces the surrounding thermal energy into molecular rotations in the crystalline states. Its rotation is confirmed by X-ray diffraction, low-temperature emission, and time-dependent density functional theory (TD-DFT), etc, which are responsible for the dynamic conformation changes in the excited states, leading to the expression of twisted intramolecular charge transfer (TICT) emission. TICT states are further identified by temperature-dependent emissions, which strengthen electronic communications between the electrondonating carbazole unit and the electron-withdrawing o-carborane moiety. As a result, significantly, the molecular rotations of o-carborane-based crystalline and its fluorescence reversible processes can be

Single-Component Color-Tunable Smart Organic Emitters with Simultaneous Multistage Stimuli-Responsiveness and Multimode Emissions

“…Traditional organic emitters with various tunable emission colors are usually achieved through molecular structure design [ 7 , 8 ], bandgap engineering refinement [ 9 – 11 ], and the construction of energy transfer hybrid systems [ 12 – 14 ]. For intelligent optoelectronic applications, i.e., multicolor displays [ 15 , 16 ], visual monitoring [ 17 – 19 ], and information encryption [ 14 , 20 ], it is desirable to develop novel smart responsive organic emitters that are able to achieve facile real-time in situ color tunability in response to external stimuli variations.…”

Fast photostimulus-responsive ultralong room-temperature phosphorescence behaviour of benzoic acid derivatives@boric acid

“…43,44 Furthermore, various optoelectronic stimulus-responsive materials based on light stimulus response have also seen tremendous developments in recent years. [45][46][47][48] The light stimulus-driven reversible dynamic properties of such functional materials are of paramount importance in the field of optoelectronics, drug delivery and photo actuators. Therefore, in the field of reversible information encryption and decryption, it is desirable to develop photostimulus luminescent materials that are capable of being facilely operated in a noninvasive manner.…”

Rotors tailoring molecular stacking for constructing multi-stimuli-responsive luminescent materials

“…17 Huang et al achieved a thermal energy-driven rotor exhibiting temperature-dependent emission. 18 Although such rotor chromophores have been reported, the complex correlation between assembly structures and emission behaviours is still unclear, which impedes the rational design of rotor chromophores.…”