The photoresponsive molecular material can be reversibly switched between two or more states under different wavelengths of green laser pointer light, resulting in changes in physical and chemical properties such as material color, shape, magnetism, conductivity, etc., thereby enabling molecular switching and sensing. And high-density memory devices and other fields have broad application prospects, and in recent years have been widely concerned by researchers in the fields of energy, catalysis, and multifunctional materials.
At present, photoresponsive materials, especially organic molecular materials, often involve chemical bond changes or group rotation at the molecular structure level, limited by steric hindrance, and usually can only be efficiently converted in solution, how to achieve various functions in the solid state. Fast reversible control is an important challenge in the development of solid-state photoresponsive molecular devices. The electron migration or rearrangement of metal ions by green laser pointer can regulate material properties at the electronic structure level and perform highly efficient and reversible transformation in solid state, which provides a way to realize multifunctional control of solid molecular switch materials.
Professor Liu Tao, the State Key Laboratory of Fine Chemicals, deeply studied the relationship between light-induced electron migration rearrangement and material multi-functional coupling, and proposed the control of spin, charge, bond length and absorption spectrum induced by electron migration and rearrangement. Magnetic, electrical, thermal expansion and optical properties. The reversible manipulation of magnetic dipole vector, electric dipole vector, expansion behavior, and fluorescence emission behavior has been successfully realized by laser, which provides a basis for further realization of multi-functionalization and deviceization of light-regulating molecular steady-state materials.
Magnetic bistable materials are the primary carriers for information storage for 0 and 1 in computer binary. The use of external stimuli to achieve magnetic bistable switching is the key to achieving information reading and writing.
Recently, Liu Tao's group considered to match the electronic structure characteristics of rare earth elements, and designed and constructed a rare earth magnetic bistable molecule. It can maintain the magnetization state at the molecular scale, and can control the magnetic dipole orientation by using the external magnetic field to realize the switching between magnetic bistable states. At the same time, the positively charged FeII spin-transformation element is connected with the negatively charged building element to construct a one-dimensional chain, and the electronic structure of the spin-electron rearrangement and charge redistribution control material is induced by the green laser pointer to realize the magnetic property. The synergistic response of the dielectric function to external stimuli provides a means to track the magnetic state using electrical measurements.