In this review, we survey the diversity of structures and functions which are encountered in advanced self-assembled nanomaterials. We highlight their flourishing implementations in three active domains of applications: biomedical sciences, information technologies, and environmental sciences. Our main objective is to provide the reader with a concise and straightforward entry to this broad field by selecting the most recent and important research articles, supported by some more comprehensive reviews to introduce each topic. Overall, this compilation illustrates how, based on the rules of supramolecular chemistry, the bottom-up approach to design functional objects at the nanoscale is currently producing highly sophisticated materials oriented towards a growing number of applications with high societal impact.

The preparation of a dimannosyl[c2]daisy chain molecular machine containing an ammonium and a triazolium station is described. The both stretched and contracted states of the molecular machine can be obtained by variation of the pH, thus localizing the mannosyl stoppers closer or farther away.

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A family of triarylamine-fullerene conjugates has been synthesized and shown to self-assemble upon light stimulation in chlorinated solvents. This light-induced process primarily involves excitation of triarylamine derivatives, which then oxidize and stack with their neutral counterparts to form charge transfer complexes in the form of p-conducting channels, while fullerenes are consequently enforced in coaxial n-conducting columnar arrangements. These supramolecular heterojunctions can be organized over very long distances in micrometric fibers when a controlled amount of photons is provided from a white light source to initiate the process. Surprisingly, when sunlight or UV light is used instead, the nanostructuration leads to monodisperse spherical objects due to the nature of the nucleation-growth process involved in the stacks formation. This control over the supramolecular morphology of organic self-assemblies using the nature of light is of general interest for the design of functional responsive materials.

The syntheses of various two- and three-station mannosyl [c2]daisy chains, based on a dibenzo-24-crown-8 macrocyclic moiety and an ammonium, a triazolium, and a mono- or disubstituted pyridinium amide station, are reported. The ability of these molecules to act as molecular machine based mimetics has been further studied by (1)H NMR studies. In all the protonated ammonium states, the interwoven rotaxane dimers adopt an extended co-conformation. However, carbamoylation of the ammonium station led to many different other [c2]daisy chain co-conformations, depending on the other molecular stations belonging to the axle. In the two-station [c2]daisy chains containing an ammonium and a mono- or disubstituted pyridinium amide station, two large-amplitude relative movements of the interwoven components were noticed and afforded either an extended and a contracted or very contracted state with, in the latter case, an impressive chairlike conformational flipping of the mannopyranose from (1)C(4) to (4)C(1). In the case of the three-station-based [c2]daisy chains containing an ammonium, a triazolium, and disubstituted pyridinium amide, an extended and a half-contracted molecular state could be obtained because of the stronger affinity of the dibenzo-24-crown-8 part for, respectively, the ammonium, the triazolium, and the disubstituted pyridinium amide. Eventually, with axles comprising an ammonium, a triazolium, and a monosubstituted pyridinium amide, an extended conformation was noticed in the protonated state whereas a continuous oscillation between half-contracted and contracted states, in fast-exchange on the NMR time scale, was triggered by carbamoylation. Variations of the solvent or the temperature allow the modification of the population of each co-conformer. Thermodynamic data provided a small free Gibbs energy ΔG of 2.1 kJ·mol(-1) between the two translational isomers at 298 K.

High-yield, straightforward synthesis of two- and three-station [2]rotaxane molecular machines based on an anilinium, a triazolium, and a mono- or disubstituted pyridinium amide station is reported. In the case of the pH-sensitive two-station molecular machines, large-amplitude movement of the macrocycle occurred. However, the presence of an intermediate third station led, after deprotonation of the anilinium station, and depending on the substitution of the pyridinium amide, either to exclusive localization of the macrocycle around the triazolium station or to oscillatory shuttling of the macrocycle between the triazolium and monosubstituted pyridinium amide station. Variable-temperature (1)H NMR investigation of the oscillating system was performed in CD(2)Cl(2). The exchange between the two stations proved to be fast on the NMR timescale for all considered temperatures (298-193 K). Interestingly, decreasing the temperature displaced the equilibrium between the two translational isomers until a unique location of the macrocycle around the monosubstituted pyridinium amide station was reached. Thermodynamic constants K were evaluated at each temperature: the thermodynamic parameters DeltaH and DeltaS were extracted from a Van't Hoff plot, and provided the Gibbs energy DeltaG. Arrhenius and Eyring plots afforded kinetic parameters, namely, energies of activation E(a), enthalpies of activation DeltaH( not equal), and entropies of activation DeltaS( not equal). The DeltaG values deduced from kinetic parameters match very well with the DeltaG values determined from thermodynamic parameters. In addition, whereas signal coalescence of pyridinium hydrogen atoms located next to the amide bond was observed at 205 K in the oscillating rotaxane and at 203 K in the two-station rotaxane with a unique location of the macrocycle around the pyridinium amide, no separation of (1)H NMR signals of the considered hydrogen atoms was seen in the corresponding nonencapsulated thread. It is suggested that the macrocycle acts as a molecular brake for the rotation of the pyridinium-amide bond when it interacts by hydrogen bonding with both the amide NH and the pyridinium hydrogen atoms at the same time.

A logic gate based on a bistable [c2] daisy chain rotaxane decorated with lateral triarylamine units is described, giving rise to an INHIBIT logic function using proton concentration and light as inputs, and producing dual color change and supramolecular self-assembly as outputs.

Molecular machines boarding now! Molecular machines containing dibenzo[24]crown-8 (DB24C8) and based on an anilinium and a pyridinium amide station have been prepared. The DB24C8 shuttles upon variation of pH and interacts differently with the pyridinium amide station depending on its substitution. When the DB24C8 sits around the disubstituted amide, the conformation of the pyranose changes from (1)C(4) to (4)C(1).