Supracluster Assembly of Archimedean Cages with 72 Hydrogen Bonds for the Aldol Addition Reaction

Clusters that can be experimentally precisely characterized and theoretically accurately calculated are essential to understanding the relationship between material structure and function. Here, we propose the concept of "supraclusters", which aim to connect "supramolecules" and "suprananoparticles" as well as reveal the unique assembly behavior of "supraclusters" with nanoparticle size at the molecular level. The implementation of supraclusters is full of challenges due to the difficulty in satisfying the ordered connectivity of clusters due to their abundant and dispersed hydrogen bonding sites. By solvothermal synthesis under a high catechol (H2 CATs) content, we successfully isolated a series of triangular {Al6 M3 } cluster compounds possessing brucite-like structural features. Interestingly, eight {Al6 M3 } clusters form 72-fold strong hydrogen bonding truncatedhexahedron Archimedean {Al6 M3 }8 supracluster cage (abbreviated as H-tcu). Surprisingly, the solution stability of the H-tcu was further proved by electrospray ionization mass spectrometry (ESI-MS) characterization. Therefore, it is not difficult to explain the reason for assembly of H-tcu into edge-directed and vertex-directed isomers. These porous supraclusters can be obtained by scale-up synthesis and exhibit a noticeable catalysis effect towards the condensation of acetone and p-nitrobenzaldehyde. As an intermediate state of supramolecule and suprananoparticle, the supracluster assembly can enrich the cluster chemistry and bring new structural types.

Superstructure-Induced Hierarchical Assemblies for Nanoconfined Photocatalysis

Most attempts to synthesize supramolecular nanosystems are limited to a single mechanism, often resulting in the formation of nanomaterials that lack diversity in properties. Herein, hierarchical assemblies with appropriate variety are fabricated in bulk via a superstructure-induced organic-inorganic hybrid strategy. The dynamic balance between substructures and superstructures is managed using covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) as dual building blocks to regulate the performances of hierarchical assemblies. Significantly, the superstructures resulting from the controlled cascade between COFs and MOFs create highly active photocatalytic systems through multiple topologies. Our designed tandem photocatalysis can precisely and efficiently regulate the conversion rates of bioactive molecules (benzo[d]imidazoles) through competing redox pathways. Furthermore, benzo[d]imidazoles catalyzed by such supramolecular nanosystems can be isolated in yields ranging from 70 % to 93 % within tens of minutes. The multilayered structural states within the supramolecular systems demonstrate the importance of hierarchical assemblies in facilitating photocatalytic propagation and expanding the structural repertoire of supramolecular hybrids.

In situ Nucleation-Growth Strategy for Controllable Heterogeneous Supramolecular Polymerization of Liquid Crystalline Block Copolymers and Their Hierarchical Assembly

The self-assembly morphologies of subunits are largely governed by thermodynamics, which plays a less important role in dimensional control. Particularly for one-dimensional assemblies from block copolymers (BCPs), the negligible energy difference between short and long ones imposes great challenges in length control. Herein, we report that by incorporating additional polymers to induce in situ nucleation and trigger the subsequent growth, controllable supramolecular polymerization driven by mesogenic ordering effect could be realized from liquid crystalline BCPs. The length of the resultant fibrillar supramolecular polymers (SP) is controlled by tuning the ratio between nucleating and growing components. Depending on the choice of BCPs, the SPs can be homopolymer-like, heterogeneous triblock, and even pentablock copolymer-like. More interestingly, with insoluble BCP as a nucleating component, amphiphilic SPs are fabricated, which can undergo spontaneous hierarchical assembly.

Hierarchical Assembly of a Micro- and Macroporous Hydrogen-Bonded Organic Framework with Tailored Single-Crystal Size

Porous organic molecular materials represent an emergent field of research in Chemistry and Materials Science due to their unique combination of properties. To enhance their performance and expand the number of applications, the incorporation of hierarchical porosity is required, as exclusive microporosity entails several limitations. However, the integration of macropores in porous organic molecular materials is still an outstanding challenge. Herein, we report the first example of a hydrogen-bonded organic framework (MM-TPY) with hierarchical skeletal morphology, containing stable micro- and macroporosity. The crystal size, from micro to centimetre scale, can be controlled in a single step without using additives or templates. The mechanism of assembly during the crystal formation is compatible with a skeletal crystal growth. As proof of concept, we employed the hierarchical porosity as a platform for the dual, sequential and selective co-recognition of molecular species and microparticles.

Encapsulation of Active Enzymes within Bacteriophage P22 Virus-Like Particles

Virus-like particles (VLPs) are nonpathogenic protein cage structures derived from viral coat proteins that have found utility in the area of biomaterials and nanotechnology. VLPs have been exploited as containers for the sequestration and encapsulation of a wide range of guest molecules in their hollow interiors. The robust nature of VLPs lend them as versatile scaffolds that can be exploited to provide protection to encapsulated guest molecules, such as enzymes which are often susceptible to inactivation and degradation, and for organization and construction of new nanomaterials incorporating the chemical properties of the guest molecules. In this chapter a background and methodology for the encapsulation of enzymes on the interior of the bacteriophage P22 derived VLP is described.

Multiscale active layer morphologies for organic photovoltaics through self-assembly of nanospheres

We address here the need for a general strategy to control molecular assembly over multiple length scales. Efficient organic photovoltaics require an active layer comprised of a mesoscale interconnected networks of nanoscale aggregates of semiconductors. We demonstrate a method, using principles of molecular self-assembly and geometric packing, for controlled assembly of semiconductors at the nanoscale and mesoscale. Nanoparticles of poly(3-hexylthiophene) (P3HT) or [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were fabricated with targeted sizes. Nanoparticles containing a blend of both P3HT and PCBM were also fabricated. The active layer morphology was tuned by the changing particle composition, particle radii, and the ratios of P3HT:PCBM particles. Photovoltaic devices were fabricated from these aqueous nanoparticle dispersions with comparable device performance to typical bulk-heterojunction devices. Our strategy opens a revolutionary pathway to study and tune the active layer morphology systematically while exercising control of the component assembly at multiple length scales.