Construction of Double-Stranded Metallosupramolecular Polymers with a Controlled Helicity by Combination of Salt Bridges and Metal Coordination

摘要

Multiple-stranded helical structures are ubiquitous in Nature,particularly in biomacromolecules,such as DNA and collagen.They are constructed through the cooperative action of several noncovalent forces and are significantly linked to their elaborate biological functions.Inspired by the biopolymers with multiple-stranded helical structures,chemists have exerted much effort to intertwine artificially designed oligo-or macromolecular strands to form multiple-stranded helical structures by utilizing noncovalent interactions.We have recently reported the rational design and synthesis of complementary double helices with optical activity,of which the strands consist of crescent-shaped m-terphenyl groups bearing chiral amidine and achiral carboxyl groups.The double helix formation with a controlled helicity is driven by the chiral amidinium-carboxylate salt bridges,which are tolerant to other various functional groups,thereby making a wide range of designs possible.