Flexible metal complex crystals in response to external mechanical stimuli

Crystal Design for Tuning the Mechanical Flexibilities of M(salophen) Complexes

“…Thus, the ε values of crystals 1 and 2 were determined to be 11.95 and 10.65%, respectively, whereas that of the Ni derivative was 10.1%. Compared with the ε values obtained for previously reported metal coordination complexes, 9 these values are relatively high and appear sufficient to indicate the generation of novel flexible crystals. Indeed, compounds 1 and 2 exhibit the second and third highest ε values reported to date, indicating that the developed method is suitable for preparing flexible crystals and tuning the flexibilities of the crystals of metal complexes.…”

“…Since the pioneering studies on the cocrystallization of caffeine with several organic molecules, − various molecules exhibiting an elastic functionality have been developed, wherein their physical properties, molecular conductivities, luminescent properties, and molecular designs have been tuned. However, despite such advances in elastic crystals based on organic compounds, the number of elastic crystals based on metal coordination complexes remains limited. − This can be partly attributed to the fact that the structural features of metal coordination complexes are influenced by several factors, including the nature of the central metal atom, the capping ligands, and the sizes and types of the counterions or solvents. Such molecular design among metal coordination complexes is advantageous for the tuning or design of crystal flexibility.…”

Photopolymerization‐Driven Macroscopic Mechanical Motions of a Composite Film Containing a Vinyl Coordination Polymer

“…[23] Furthermore, there is scope for generating systems that are sensitive to the wavelength and intensity of the light stimulus, which presents the prospect of sophisticated photoactuation applications. [24,25] Due to the microscopic atomic displacements and the strong structural resistance inside the materials, it is still a great challenge to achieve the direct photomechanical motions of photoresponsive materials or devices on a macroscopic scale. [26] In order to develop devices that can perform photomechanical movements on a macroscopic level, the most important issue is to find or design suitable compounds that can undergo photoreactions such as photoisomerization, photocycloaddition.…”

“…As a branch of stimuli‐responsive materials, photoactuators are particularly attractive because they can be triggered in a noncontact process [23] . Furthermore, there is scope for generating systems that are sensitive to the wavelength and intensity of the light stimulus, which presents the prospect of sophisticated photoactuation applications [24, 25] . Due to the microscopic atomic displacements and the strong structural resistance inside the materials, it is still a great challenge to achieve the direct photomechanical motions of photoresponsive materials or devices on a macroscopic scale [26] .…”

Stimuli-responsive flexible organic crystals

“…Firstly, due to few internal defects and long-range structural order, crystalline materials have faster response speed and higher energy transfer efficiency. 25 Secondly, based on the designable feature of molecules, it is convenient to fabricate functional materials with different stimuli-responsive properties to meet different application requirements. 4,20 Thirdly, the molecular conformation and structural packing in crystals can be obtained by techniques such as single-crystal diffraction and in situ spectroscopy, which provide data support for the study of stimuli-response mechanisms and structure-property relationships at the molecular and supramolecular level.…”