Hierarchical Self‐Assembly of Supramolecular Coordination Polymers Using Giant Metal–Organic Nanocapsules as Building Blocks

Abstract

Controlling the self-assembly of giant molecular building blocks into complex architectures with similar hierarchy to biological species remains a major challenge in supramolecular chemistry. Akin to protein structure, here we present the self-assembly of giant molecular nanocapsules into supramolecular coordination polymers with controlled hierarchy from primary to secondary and tertiary structures. First, we successfully prepared discrete nanocapsules (secondary structures) consisting of multicomponents, such as organic macrocycles and metal-based secondary building units (primary structures). Second, these nanocapsules can self-organize into various 2D and 3D supramolecular coordination polymers (tertiary structures) through coordination-driven assembly. The periphery 24 flexible alkyl chains and 24 metal ions available for potential coordination make these nanocapsules comparable to functionalized solid nanoparticles with non-specific binding sites at the surface and allow the nanocapsules to self-adjust their orientations and coordination modes to facilitate the self-assembly process. This study sheds light on the self-assembly of giant building units with complex molecular structures and opens up possibilities for the design of new hierarchical architectures with innovative properties and functions in many applications such as biomimics, biomedicine, and molecular devices.

A Supramolecular Coordination‐Polymer‐Derived Electrocatalyst for the Oxygen Evolution Reaction

“…Recently, we further demonstrated that these hexameric nanocapsules can self‐organize into various 2D and 3D supramolecular coordination polymers (SCPs) by using C‐propan‐3‐ol pyrogallol[4]arene . For example, in SCP‐3‐Ni, each Ni 24 L 6 nanocapsule is connected with eight others through eight alkyl chains . Moreover, compared with discrete nanocapsules and 2D SCPs, SCP‐3‐Ni as a representative 3D SCP shows an improved stability in the solid state upon loss of solvent molecules and exposure to air.…”

“…Herein, we adopted SCP‐3‐Ni as the precursor and successfully in situ prepared iron oxide decorated nickel iron alloy nanoparticles anchored on laser induced graphene (denoted as FeNi 3 –Fe 3 O 4 NPs/LIG) via laser induced solid phase reaction. SCP‐3‐Ni was prepared by our previously reported solvo‐thermal reaction between C‐propan‐3‐olpyrogallol[4]arene and nickel nitrate (see Supporting Information for more details) . Thereafter, as shown in the Figure a, SCPs were dispersed in acetonitrile containing FeCl 3 and then dropped onto the as‐synthesized LIG.…”

“…[8] For example, in SCP-3-Ni, each Ni 24 L 6 nanocapsule is connected with eight others through eight alkyl chains. [9] Moreover,c ompared with discrete nanocapsules and 2D SCPs, SCP-3-Ni as ar epre-sentative3 DS CP shows an improved stabilityi nt he solid state upon loss of solventm olecules and exposure to air.A so ne class of metal-organic compounds,t hese SCPs show prominent potential as precursors in the preparationo fn anocatalysts compared to conventional MOFs. The confinement effect of the nanocapsules may effectively prevents agglomeration of nanoparticles during thermalt reatment and offerso pportunities for the formationof nanocatalysts downt on ano or even atomic size.…”

“…SCP-3-Ni was prepared by our previouslyr eported solvo-thermalr eactionb etween C-propan-3-olpyrogallol [4]arene and nickel nitrate (see Supporting Information for more details). [9] Thereafter,a ss hown in the Figure 1a,S CPs were dispersedi na cetonitrile containing FeCl 3 and then dropped onto the as-synthesized LIG. The dried LIG/SCPs/FeCl 3 precursor was subsequently scribed by the CO 2 laser in the air.T he transient generated high temperature and pressure can decomposet he SCP-3-Ni in as hort time and facilitate the formation of the final product.T he obtained FeNi 3 -Fe 3 O 4 NPs/LIG catalyst dis-plays remarkable OER catalytic performance, in terms of al ow overpotential of 274 mV at 10 mA cm À2 ,asmall Tafel slope of 37 mV dec À1 ,a sw ell as excellent stability,s howing as uperior performance to the state-of-the-artRuO 2 electrocatalyst.…”

Hydrogen Bonding Guests Direct the Packing of a Small Organic Cage Molecule

“…Ideally, this would involve taking a discrete cage molecule and using additional interactions to drive formation of a porous crystalline 3D network. Significant progress has recently been made in this area with covalent bond formation, [6][7] metal-ligand coordination [8][9][10][11][12][13][14][15][16] and noncovalent forces [17][18][19][20][21][22][23][24] being used to drive framework assembly.…”