Foldecture as a Core Material with Anisotropic Surface Characteristics

Abstract

The synthesis of microscale, polyhedrally shaped, soft materials with anisotropic surface functionality by a bottom-up approach remains a significant challenge. Herein we report a microscale molecular architecture (foldecture) with facet-dependent surface characteristics that can potentially serve as a well-defined catalytic template. Rhombic rod shaped foldectures with six facets were obtained by the aqueous self-assembly of helical β-peptide foldamers with a C-terminal carboxylic acid. An analysis of the molecular packing by X-ray diffraction revealed that carboxylic acid groups were exposed exclusively on the two (001) rhombic facets due to antiparallel packing of the helical peptides. A surface energy calculation by molecular dynamics simulation was performed to provide a plausible explanation for the development of anisotropy during foldecture formation. The expected facet-selective surface properties of the foldecture were experimentally confirmed by selective deposition of metal nanoparticles on the (001) facets, leading to a new class of sequentially constructed, heterogeneous "foldecture core" materials.

Scrolling of Supramolecular Lamellae in the Hierarchical Self-Assembly of Fibrous Gels

“…35 Similarly, solvation of growing surfaces can lead to large differences in their relative surface energies, producing the anisotropic growth conditions required for gel formation. 36 To aid the identification of effective LMWGs, it is important to develop detailed computational models of the gelation process. Provided the system is well-parameterized and the force field carefully chosen, MD simulations can replicate the key results of more realistic but computationally expensive calculation techniques.…”

“…It is possible that such values could be estimated more quickly by subtracting the energy of the simulated crystal bulk from that of a surface slab. 35,36 An advantage of the approach used in this study is that increasing N resembles the actual process of aggregation. Furthermore, the discrete crystallites are closer analogs to real assemblies than an infinite periodic lattice, and the calculation of a gradient through multiple points allows the precision of g to be easily assessed.…”

Magnetotactic molecular architectures from self-assembly of β-peptide foldamers

“…Molecular packing in the foldectures was investigated using powder X-ray diffraction combined with single-crystal and electron diffraction experiments ( Supplementary Fig. 3 ) 19 21 . The diamagnetic susceptibilities along the three orthogonal crystallographic a , b and c axes of the orthorhombic lattices were calculated using density functional theory (DFT).…”

“…Recently, we reported unprecedented three-dimensional molecular architectures, named ‘foldectures', derived from self-assembly of β-peptide foldamers consisting of trans -( S , S )-2-aminocyclopentanecarboxylic acids ( trans -ACPC) 16 17 18 19 . Trans -ACPC oligomers have exceptional helical stability and predictable intermolecular interactions 20 21 , and can therefore self-assemble under aqueous conditions to form unique anisotropic microstructures with controllable shapes, sizes and crystallinities.…”

Attempt to visualize terminal structure on a specific facet in polymer–metal complex nanocrystals

“…It is, however, oen difficult to not only control but also characterize the surface structure and properties of NCs. In general, since unsaturated bonds (or dangling bonds) are hardly exposed on the surface of organic bulk crystals and/or organic NCs, surface modication is typically performed through physical adsorption, [1][2][3][4] instead of chemical adsorption induced by covalent bond formation.…”