Macromolecular semi-rigid nanocavities for cooperative recognition of specific large molecular shapes

Abstract

Molecular shape recognition for larger guest molecules (typically over 1 nm) is a difficult task because it requires cooperativity within a wide three-dimensional nanospace coincidentally probing every molecular aspect (size, outline shape, flexibility and specific groups). Although the intelligent functions of proteins have fascinated many researchers, the reproduction by artificial molecules remains a significant challenge. Here we report the construction of large, well-defined cavities in macromolecular hosts. Through the use of semi-rigid dendritic phenylazomethine backbones, even subtle differences in the shapes of large guest molecules (up to B2 nm) may be discriminated by the cooperative mechanism. A conformationally fixed complex with the best-fitting guest is supported by a three-dimensional model based on a molecular simulation. Interestingly, the simulated cavity structure also predicts catalytic selectivity by a ruthenium porphyrin centre, demonstrating the high shape persistence and wide applicability of the cavity.

Epitaxially Grown Ultra-Flat Self-Assembling Monolayers with Dendrimers

“…Their compact structures allow for the formation of various higher order self-assembling structure owing to the weak and omnidirectional intermolecular interactions [ 7 , 8 ]. The material used in this study is phenylazomethine dendrimers with a zinc porphyrin core ( 1 ) [ 9 , 10 , 11 ]. Furthermore, this dendrimer has a capability for the precise accumulation for various metal ions [ 12 ] and organic molecules [ 13 , 14 ] in the interior.…”

“…Furthermore, this dendrimer has a capability for the precise accumulation for various metal ions [ 12 ] and organic molecules [ 13 , 14 ] in the interior. Therefore, it is a suitable molecule with many potential post-functionalization such as templated cluster synthesis [ 15 , 16 , 17 , 18 , 19 ], molecular shape recognition [ 11 ], anisotropic charge transfer [ 10 , 20 , 21 , 22 ], and further extension of the structural dimensions [ 23 , 24 ]. The dendrimer 1 ( Figure 1 ) was synthesized according to a literature method [ 9 ] and deposited on the atomically flat surfaces of substrates including mica, HOPG (highly ordered pyrolytic graphite), and Au(111).…”

A Robust Strategy for Precise Fabrication of Rigid–Flexible Coupling Dendrimers toward Self-Coordinated Hierarchical Assembly

“…According to the anatomy of core-shell-type architectures and rigidity of interior kernels, dendrimers could be mainly divided into two categories: (1) rigid core dendrimers, based on the traditional horizontal periodic elemental features associated with conducting or semiconducting properties, [11][12][13][14][15][16] tend to form crystalline or rigid 3D lattices with uniform size and fixed shape. For example, Au NP cores possess uniform nanometer size and shape that could prevent adjacent rigid cores from deforming in the self-assembly process, thus limiting the multiformity of assembled morphologies; [17][18][19] (2) flexible core dendrimers, including those materials with organic-like structures in correlation with pliable abilities, possess a variety of interchangeable chain conformations, which are apt to curl and entangle with each other to facilitate the hydrophobic areas, forming a series of random heterogeneous aggregates. [20][21][22] Among them, regulation protocols that enable the simple production and convenient tailoring of dendritic building blocks with specific geometry and symmetry are of key general importance, but most of the techniques are subject to limited syntheses, monotone structures, and sophisticated controls.…”

Amino Acid‐Dependent Host–Guest Interaction: Polyglycerol Dendrimer of Generation 3 Encapsulates Amino Acids Bearing Two Amino Groups

“…Yamamoto et al. suggested molecular shape recognition and systematically demonstrated encapsulation of fullerenes, ferrocene derivatives and metal ions using semi‐rigid dendritic phenylazomethine backbones. Müllen et al.…”