The double helix of DNA epitomizes this molecule's ability to self-assemble in aqueous solutions into a complex chiral structure using hydrogen bonding and hydrophobic interactions. Non-covalently interacting molecules in organic solvents are used to design systems that similarly form controlled architectures. Peripheral chiral centres in assemblies and chiral side chains attached to a polymer backbone, have been shown to induce chirality at the supramolecular level, and highly ordered structures stable in water are also known. However, it remains difficult to rationally exploit non-covalent interactions for the formation of chiral assemblies that are stable in water, where solvent molecules can compete effectively for hydrogen bonds. Here we describe a general strategy for the design of functionalized monomer units and their association in either water or alkanes into non-covalently linked polymeric structures with controlled helicity and chain length. The monomers consist of bifunctionalized ureidotriazine units connected by a spacer and carrying solubilizing chains at the periphery. This design allows for dimerization through self-complementary quadruple hydrogen bonding between the units and solvophobically induced stacking of the dimers into columnar polymeric architectures, whose structure and helicity can be adjusted by tuning the nature of the solubilizing side chains.

Extremely effective cooperative effects operate during the formation of chiral stacks of C3‐symmetrical molecules in alkane solvents (a molecule is depicted on the right). The sergeants‐and‐soldiers principles as well as chiral solvation lead to a preferred helical sense in the columnar aggregates. The amplification of chirality in dynamic systems shows the precision in aggregation.

Hydrogen bonded C(3)-symmetrical molecules that associate into supramolecular stacks are described. Structural mutation on these molecules has been performed to elucidate the contribution of the different secondary interactions (hydrogen bonding, pi-pi stacking) to the self-assembly of the disks into chiral stacks. Twelve C(3)-symmetrical molecules have been investigated, six of which contain three central amide functionalities (1a-f) and six of which contain three central urea groups (2a-f). Peripheral groups of the disks are "small", "medium", or "large", half of them being achiral and the other half being chiral, to enable investigation of the supramolecular architectures with CD spectroscopy. In all of the cases, elongated, helical stacks are formed in apolar solution, except for the "medium" amide disks 1c/d. The elongated stacks of the C(3)-symmetrical disks form gels, which are visualized by AFM and SANS, and this confirms the directionality of the interactions. For the "large" urea disk, 2f, fibers with a length of up to 2 microm are observed. Temperature dependent and "sergeants-and-soldiers" CD measurements reveal that the urea stacks are much more rigid than the corresponding amide ones. In case of the "medium" urea disks, 2c/d, a true rigid rod, is formed. Where amide disks immediately reach their thermodynamic equilibrium, kinetic factors seem to govern urea aggregation. In a number of experiments aimed at reversibility with the urea stacks, hysteresis is observed, implying that these urea disks initially form a poorly defined stack, which subsequently transforms slowly into a well-defined, chiral architecture.

The location of nine chiral penta(ethylene oxide) side chains at the periphery of a C 3 -symmetrical hydrogen-bonded extended core gives rise to a thermotropic discotic liquid crystalline material that shows lyotropic phases in polar, protic media. The molecular stacks self-assemble in a reversible and hierarchical fashion, and specific and subtle solvent-molecule interactions together with the created hydrophobic microenvironment account for an unprecedented stabilization of a preferred handedness of the helical stacks by cooperative intermolecular interactions. The presence of either chirality or achirality at the supramolecular level in the stacks can be tuned by temperature and solvent as judged from circular dichroism spectroscopy. A hierarchical growth of the self-assembly is revealed using a variety of spectroscopic techniques and differential scanning calorimetry.