Discrete Supracrystalline Heterostructures from Integrative Assembly of Nanocrystals and Porous Organic Cages

Abstract

Although self-assembly across multiple length scales has been well recognized and intensively investigated in natural biological system, the design of artificial heterostructures enabled by integrative self-assembly is still in its infancy. Here we report a strategy toward the growth of discrete supracrystalline heterostructures from inorganic nanocrystals and porous organic cages (CC3- R), which in principle relies on the host–guest interactions between alkyl chains coated on nanocrystals and the cavity of cage molecules. Density functional theory calculation indicates that an attractive energy of ∼−2 k BT is present between an alkyl chain and the cavity of a CC3- R molecule, which is responsible for the assembly of nanocrystal superlattices on the CC3- R octahedral crystals. Of particular interest is that, determined by the shape of the nanocrystals, two distinct assembly modes can be controlled at the mesoscale level, which eventually produce either a core/shell or heterodimer supracrystalline structure. Our results highlight opportunities for the development of such a noncovalent integrative self-assembly not limited to a particular length scale and that could be generally applicable for flexible integration of supramolecular systems.

Anisotropic Assembly of Nanocrystal/Molecular Hierarchical Superlattices Decoding from Tris‐Amide Triarylamines Supramolecular Networks

“…The interparticle distance between Au nanocrystals within the nanocrystal ribbons is ≈2.5 nm, which is in agreement with the previous report by solvent evaporation method. [ 18 ] The width of the nanocrystal ribbons, from single‐nanocrystal‐diameter to multiple‐nanocrystal‐diameter width, can be modulated by adding various amounts of Au nanocrystals with α in the range from 0.1 to 1.0 (Figure 4b,c). On increasing the width of the nanocrystal ribbons, the dipolar coupling between Au nanocrystals is enhanced, as evidenced from a bathochromic shift in the UV–vis spectra in the range between 500 and 600 nm (Figure 4d).…”

“…[ 12 ] The latter template‐directed strategy is more applicable to achieve hierarchically assembled structures with pre‐determined configurations. Numerous templates, including 1D carbon nanotubes, [ 13 ] anodic aluminum oxide channels, [ 14 ] natural viruses, [ 15 ] DNA scaffolds/origami, [ 16 ] 2D surfactant lamellar structures, [ 17 ] and porous organic cage crystals [ 18 ] have been demonstrated to be intriguing for directing the assembly of nanocrystals into intricate superstructures. Despite these progresses, two significant challenges still need to be addressed in directed assembly of nanocrystals including i) the interaction energy between template and nanocrystals matches well with the one between nanocrystals, which enables the formation of diverse nanocrystal superstructures without the need of surface modification of nanocrystals; ii) achieving synergistic hybrids with both components including the templates and nanocrystals contributing to the overall functionality of the nanocomposites.…”

Nanoparticle superlattices enabled by soft epitaxial strategy

“…图 7 (a) 金纳米晶体在POC分子笼上的自组装示意图; 不 同放大倍率的Au/POC复合组装体的SEM图像(b, c)和TEM 图像(d, e); (f) 两个金纳米晶体超晶格单层膜重叠的示意 图 [50] (网络版彩图) [52] ; (c) 纳米粒子超晶格薄膜表面 的SEM表征; (d) 纳米粒子薄膜缓解晶格失配引起的弹性应 变 [53] (网络版彩图)…”

“…TEM images of directed assembly of Au nanocrystals by TATA-C7-4 (d, e), TATA-C7-1′ (f, g) supramolecular structures [40] (color online). [40] (网络版彩图) 图像 [50] (网络版彩图) "软的"可编程的原子等价物来生长异质外延胶体薄 膜 [53] .…”

Folding of two-dimensional nanoparticle superlattices enabled by emulsion-confined supramolecular co-assembly

“…[10][11][12] Recently, we showed that a monolayer NP superlattice could be formed from co-assembly of a porous organic cage (POC) and NPs, where strong interaction between the aliphatic chains coated on the NPs and the cavity of the POC directs the assembly of NPs into 2D monolayer superlattices on the POC colloidal crystals, resembling the epitaxial process in atomic crystals. 13 Moreover, a monolayer NP superlattice could also be formed by templating the supramolecular assemblies from triphenylamine (TPA) derivatives within emulsion droplets. 14 However, either the POC crystals or the TPA supramolecular structures have shape-persistent nanostructures, which hampers their further evolution into more complex superstructures.…”