Metal–Organic Frameworks with Mechanically Interlocked Pillars: Controlling Ring Dynamics in the Solid-State via a Reversible Phase Change

Facile construction of fluorescent polymeric aggregates with various morphologies by self-assembly of supramolecular amphiphilic graft copolymers

Facile construction of fluorescent polymeric aggregates with various morphologies was realized by self-assembly of supramolecular amphiphilic graft copolymers.

Supramolecular inclusion-based molecular integral rigidity: a feasible strategy for controlling the structural connectivity of uranyl polyrotaxane networks

The assembly of 2D uranyl–organic rotaxane networks with well-defined channels has been achieved through an integration strategy from jointed pseudorotaxanes.

Organic nanofibers embedding stimuli-responsive threaded molecular components

While most of the studies on molecular machines have been performed in solution, interfacing these supramolecular systems with solid-state nanostructures and materials is very important in view of their utilization in sensing components working by chemical and photonic actuation. Host polymeric materials, and particularly polymer nanofibers, enable the manipulation of the functional molecules constituting molecular machines and provide a way to induce and control the supramolecular organization. Here, we present electrospun nanocomposites embedding a self-assembling rotaxane-type system that is responsive to both optical (UV-vis light) and chemical (acid/base) stimuli. The system includes a molecular axle comprised of a dibenzylammonium recognition site and two azobenzene end groups and a dibenzo[24]crown-8 molecular ring. The dethreading and rethreading of the molecular components in nanofibers induced by exposure to base and acid vapors, as well as the photoisomerization of the azobenzene end groups, occur in a similar manner to what observed in solution. Importantly, however, the nanoscale mechanical function following external chemical stimuli induces a measurable variation of the macroscopic mechanical properties of nanofibers aligned in arrays, whose Young's modulus is significantly enhanced upon dethreading of the axles from the rings. These composite nanosystems show therefore great potential for application in chemical sensors, photonic actuators, and environmentally responsive materials.

Construction of supramolecular organogels and hydrogels from crown ether based unsymmetric bolaamphiphiles

Bolaamphiphilic low-molecular-weight gelators based on crown ethers, which could form organogels and hydrogels, were prepared.