title: Well-defined secondary structures.
abstract: Molecules and assemblies of molecules with well-defined secondary structures have been designed and characterized by controlling noncovalent interactions. By specifying intermolecular interactions, a class of information-storing molecular duplexes have been successfully developed. These H-bonded molecular duplexes demonstrate programmable, sequence-specificity and predictable, tunable stabilities. Based on these highly specific molecular zippers (or glues), a systematic approach to designing self-assembled structures is now feasible. Duplex-directed formation of beta-sheets, block copolymers and templated organic reactions have been realized. By specifying intramolecular noncovalent interactions, a backbone-rigidification strategy has been established, leading to unnatural molecular strands that adopt well-defined, crescent or helical conformations. The generality of this backbone-rigidification strategy has been demonstrated in three different classes of unnatural oligomers: oligoaramides, oligoureas and oligo(phenylene ethynylenes). Large nanosized cavities have been created based on the folding of these helical foldamers. Tuning the size of the nanocavities has been achieved without changing the underlying helical topology. These helical foldamers can serve as novel platforms for the systematic design of nanostructures.
authors.affiliation: Department of Chemistry, 811 Natural Sciences Complex, University at Buffalo, State University of New York, Buffalo, NY 14260, USA.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Sanford
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamato
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Yang
authors.forename: Lihua
authors.initials: L
authors.lastname: Yuan
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Han
authors.forename: Bing
authors.initials: B
authors.lastname: Gong
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D036103:Nanotechnology; D010455:Peptides / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D010455:Peptides