Driven Evolution of a Constitutional Dynamic Library of Molecular Helices Toward the Selective Generation of [2 × 2] Gridlike Arrays under the Pressure of Metal Ion Coordination

Constitutional dynamics, self-assembly, and helical-folding control are brought together in the
efficient Sc(OTf)3/microwave-catalyzed transimination of helical oligohydrazone strands, yielding highly
diverse dynamic libraries of interconverting constituents through assembly, dissociation, and exchange of
components. The transimination-type mechanism of the ScIII-promoted exchange, as well as its regioselectivity, occurring only at the extremities of the helical strands, allow one to perform directional terminal
polymerization/depolymerization processes when starting with dissymmetric strands. A particular library is
subsequently brought to express quantitatively [2 × 2] gridlike metallosupramolecular arrays in the presence
of ZnII ions by component recombination generating the correct ligand from the dynamic set of interconverting
strands. This behavior represents a process of driven evolution of a constitutional dynamic chemical system
under the pressure (coordination interaction) of an external effector (metal ions).