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After a brief discussion of the discovery of covalent and self-organizable dendrons, dendrimers, and dendronized macromolecules, examples of cooperative, anti-cooperative and synergistic supramolecular-interactions mediating self-assembly and self-organization of supramolecular dendrimers will be presented. Dendronized crown-ethers will be used to demonstrate these interactions generated by cation-dipole, π–π stacking, H-bonding, fluorination, the specialty of Professor Giuseppe Resnati celebrated with this occasion, and covalent macromolecular interactions. It will be demonstrated that fluorination of self-assembling dendrons generates a simple approach to dendronized donors and acceptors and of their donor-acceptor complexes. The evolution of helical chirality from its discovery in tobacco mosaic virus-like supramolecular dendrimers to helical-globular-dendrimers producing chiral Frank-Kasper and quasicrystal periodic and quasiperiodic arrays will be highlighted. Helical Aquaporin-like transmembrane proteins and spherical containers will be assembled from dendritic dipeptides by a combination of H-bonding and aromatic π–π interactions. The work of Giulio Natta will be honored by a discussion of the dendronized helical stereoisomers of poly(phenylacetylene) and their intramolecular electrocyclization. Polymer chemistry will be employed as a tool to support the quasi-equivalence of self-assembling dendrons and elaborate their shape inversion from helical spheres to helical columns. Helical supramolecular dendrimers induce a helical conformation into atactic-polymer backbones, a dream which even Giulio Natta could not think of. Hydrophobic, H-bonding and ion-ion interactions generated self-assembling amphiphilic Janus dendrimers and glycodendrimers which mimic cell membranes, their glycans, and provide one-component multifunctional sequence-defined ionizable amphiphilic Janus dendrimers which target the delivery of mRNA to specific organs for stable vaccines and therapeutics. 

Previously our laboratory reported complex helical columnar, cubic, tetragonal, and liquid quasicrystal periodic and quasiperiodic functional helical arrays (including homochiral) self-organized from supramolecular dendrimers. They have attracted the interest of theoreticians and have been discovered in many other areas of soft matter, creating a new field of research. Here we report the discovery, to the best of our knowledge, of an unprecedentedly complex Pm 3¯ m cubic phase self-organized from 29 distorted globular supramolecular dendrimers with similar internal organization exhibiting five different shapes. This cubic periodic array resembles the tetragonal periodic structure, which is self-organized from 30 supramolecular dendrimers containing five differently distorted globular shapes. The thermodynamically controlled transition between these two closely related ordered arrays, hierarchically self-organized via a crown-like secondary structure, addresses key questions concerning the reversible conversion between tetragonal and cubic arrangements of 30 and 29 globular supramolecular dendrimers distorted in each case in five different ways. These results enlarge the diversity of periodic arrays of the Pm3¯m space group, raising fundamental enquiries related to the origins of order and homochirality in natural sciences. 

Helical homochirality is available in nature, biology, and, most recently, also in synthetic systems. Selected examples of helical complex systems from nature, biology, and synthetic chemistry will be briefly discussed, most probably for the first time, in a single publication. When available, the mechanisms of the origin of their homochirality will be presented. In order to encourage new discoveries, the historical events of many discoveries will also be highlighted. Potential connections between homochirality in nature and biology, as well as in nature- and bio-inspired macroscopic, molecular, and supramolecular complex systems, will be mentioned. 

This account discusses the accidental discovery of self-assembling and self-organizable dendrons, dendrimers, and dendronized polymers. Our laboratory never intended to make this discovery. At the time of this finding, our laboratory was interested in developing a methodology to mimic the self-assembly of helical rod-like and icosahedral or spherical viruses. An attempt to transform a monotropic biaxial nematic (N_b) phase of a compound constructed from a combination of a half-disc and a rod into an enantiotropic phase by attaching this building block as a side group to a polymer led to a polymer coated with a helical dendritic jacket appearing as a primitive rod-like virus. Investigation of more and less complex variants of the half-disc and rod compound led to the discovery of self-organizable dendrons, dendrimers, and dendronized polymers assembling into both helical rod-like and spherical helices supramolecular dendrimers. The combination of a disc-like and a rod-like compound that never exhibits the N_bphase was developed in France and published in this journal. Our discovery provided an example in which an incorrect assignment of a phase led to a finding that facilitated the development of several new unrelated research fields, all pioneered by self-assembling and self-organizable dendrons, dendrimers, and dendronized polymers. We would like to use this opportunity to thank the scientists who elucidated the structure and the mechanism of self-assembly of viruses, the laboratory that developed the combination of disc-like and rod-like molecules, and the scientists who asked us to investigate this molecule for providing the inspiration for this discovery. 

Our laboratory has reported an unprecedented cogwheel mechanism of helical self-organization, which generates microdomains of single-handed supramolecular columns while disregarding the chirality of its building blocks. Discovered with a dendronized perylene bisimide (PBI), this mechanism arranges the alkyl groups of the self-assembling dendrons parallel to the helical column, providing the most compact helical construct known. Four precise molecular elements were originally considered to be required by the design of this helical structure. The first three elements─alkyl group length, the presence of a chiral methyl group on the alkyl chain, and the parallel arrangement of the helical coat to the column long axis─were demanded by a dimer of the dendronized PBI with 45° internal rotation of PBI units within dimer and a 90° rotation of dimers along the column long axis. Previous experiments demonstrated that a self-repairing process relaxes the number of carbons and eliminates the need for a chiral methyl group within the alkyl chains of the dendronized building block, essential to predict the helical half-pitch and helical coat arrangement. In this work, we demonstrate that the PBI dimer can be replaced by a repeat unit formed from one PBI and three nondendronized aromatic groups. Combined with the previously reported results, this extraordinary tolerance of the cogwheel mechanism to structural defects places it high on the list of models to study the origins of biological homochirality and for numerous practical applications. 

Living cationic ring‐opening polymerization accompanied by isomerization of cyclic imino ethers is performed at high temperatures that provide access to the synthesis of self‐organizable systems in their isotropic melt or solution state. This Perspective discusses fundamental mechanistic principles of this polymerization and bridges with the polymerization of dendronized cyclic iminoethers forming polymers that self‐organize soft Frank–Kasper and quasicrystal periodic and quasiperiodic arrays. These two fields represent frontiers in macromolecular and supramolecular science. A brief discussion of the impact of this polymerization on biomaterials and how it impacted contemporary mechanistic investigations is also made. Expected impacts via future synthetic developments and mechanistic investigations are discussed.