Dynamic molecular crystals with switchable physical properties

Abstract

The development of molecular materials whose physical properties can be controlled by external stimuli - such as light, electric field, temperature, and pressure - has recently attracted much attention owing to their potential applications in molecular devices. There are a number of ways to alter the physical properties of crystalline materials. These include the modulation of the spin and redox states of the crystal's components, or the incorporation within the crystalline lattice of tunable molecules that exhibit stimuli-induced changes in their molecular structure. A switching behaviour can also be induced by changing the molecular orientation of the crystal's components, even in cases where the overall molecular structure is not affected. Controlling intermolecular interactions within a molecular material is also an effective tool to modulate its physical properties. This Review discusses recent advances in the development of such stimuli-responsive, switchable crystalline compounds - referred to here as dynamic molecular crystals - and suggests how different approaches can serve to prepare functional materials.

Introduction to Electronic Properties and Dynamics of Organic Complexes as Self‐Assembled Monolayers

“…This family of compounds, named "dynamic molecular solids", is discussed in Ref. [16], where the author shows how fundamental is the control of electron, proton, and molecular motion. For example, a photo-induced molecular structural change could be used to control magnetic properties of the molecular solid.…”

“…Molecular crystalline materials can be altered by manipulating spin, electron transfer, proton transfer, molecular structure, and orientation, leading to dynamical switchable properties [16] by external stimuli such as light, electric field, and temperature. The precise control of the switching properties is the focus of recent frontier developments.…”

Model of ultrafast demagnetization driven by spin-orbit coupling in a photoexcited antiferromagnetic insulator Cr2O3

“…In addition to the great theoretical interest in understanding the nonequilibrium dynamics in materials, it could be applied technically to the magnetic or electronic recording. [1][2][3][4][5] The photoinduced change of physical properties is often attributed to thermal effects because the photon energy eventually is redistributed among interacting charge, spin, and lattice degrees of freedom, and increases the system temperature instantly. 6 On the other hand, photoirradiation may induce non-thermal metastable states or transient phases with optical, magnetic and electric properties distinct from that of the ground states.…”

Halogen Substituent Effect on the Spin-Transition Temperature in Spin-Crossover Fe(III) Compounds Bearing Salicylaldehyde 2-Pyridyl Hydrazone-Type Ligands and Dicarboxylic Acids

“…In terms of practical applications, it is preferable for the spin-transition temperature to be near room temperature. Therefore, the effects of replacing anion and solvent molecules and the introduction of substituents into ligands on the spin-transition temperature have been actively studied for many types of SCO complexes [4][5][6][7][8][9][10][11][12][13][14][15][16].…”