From Double-Stranded Helicates to Abiotic Double Helical Supramolecular Assemblies.

The folding of oligomeric strands is the method that nature has selected to generate ordered assemblies presenting spectacular functions. In the purpose to mimic these biomacromolecules and extend their properties and functions, chemists make important efforts to prepare artificial secondary, tertiary, and even quarternary structures based on folded abiotic backbones. A large variety of oligomers and polymers, encoded with chemical informations, were designed, synthesized and characterized, and the establishment of non-covalent interactions lead to complex and functional supramolecular architectures resulting from a spontaneous self-assembly process. The association of complementary molecular strands into double helical structures is a common structural pattern of nucleic acids and proteins, so the synthesis of bio-inspired double helices has emerged as an important subject. In recent years, a number of synthetic oligomers have been reported to form stable double helices and it was shown that the equilibrium between single and double helices can be controlled via different stimuli like the modification of the solvent or the temperature. This kind of structure presents highly interesting functions, such as molecular recognition within the cavity of double helices, and some other potential applications will emerge in the future.