Molecular Springs: Integration of Complex Dynamic Architectures into Functional Devices

Abstract

Molecular/supramolecular springs are artificial nanoscale objects possessing well‐defined structures and tunable physicochemical properties. Like a macroscopic spring, supramolecular springs are capable of switching their nanoscale conformation as a response to external stimuli by undergoing mechanical spring‐like motions. This dynamic action offers intriguing opportunities for engineering molecular nanomachines by translating the stimuli‐responsive nanoscopic motions into macroscopic work. These nanoscopic objects are reversible dynamic multifunctional architectures which can express a variety of novel properties and behave as adaptive nanoscopic systems. In this Minireview, we focus on the design and structure–property relationships of supramolecular springs and their (self‐)assembly as a prerequisite towards the generation of novel dynamic materials featuring controlled movements to be readily integrated into macroscopic devices for applications in sensing, robotics, and the internet of things.

Emerging Spacers‐Based Ligands for Supramolecular Coordination Complexes

“…Fully aliphatic spacer based building blocks are challenging in terms of their low predictability and selectivity in making coordination driven supramolecules [34] . On the other hand, flexible aliphatic chain spacer based ligands can offer supramolecular assemblies with unique topologies and host‐guest properties [35,36] . The SCCs having lengthy aliphatic chain spacer‐based ligands can be stabilized by London dispersion forces when these chains are confined in metalloarchitecture [37] .…”

Molecular Spring‐like Triple‐Helix Coordination Polymers as Dual‐Stress and Thermally Responsive Crystalline Metal–Organic Materials

“…This spring-like regulation behavior of helical chains originated from the softness of organic linker is similar to that found in hydrogen bond chains of crystalline amino acids on compression. [16] Based on the dynamic expansion of helical chain upon tensile elaborated above,i tc an be inferred that the capability of 1D coordination polymer chains to undergo spring-like stretching and contraction [17] through reversible structural reorganization is crucial to the macroscopic mechanical elasticity of the bulky crystal.…”

Light-fueled dynamic covalent crosslinking of single polymer chains in non-equilibrium states

“…2 In contrast to equilibrium driven chemistry, all living organisms consume fuel to operate far from equilibrium states -otherwise life could not exist. 3,4 The vast potential of dynamic non-equilibrium materials has inspired a wide range of synthetic systems over the last decade comprising life-like properties. 5 To design chemical systems that consume fuel to acquire a higher energetic state and dissipate back into the original state in the absence of fuel, the use of natural building blocks provides an attractive avenue.…”