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

摘要

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 Sc~(III)-promoted exchange,as well as its regio-selectivity,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 x 2] gridlike metallosupramolecular arrays in the presence of Zn~(II) 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).