Programmable dynamic covalent nanoparticle building blocks with complementary reactivity

Abstract

A toolkit of two complementary dynamic covalent nanoparticles enables programmable and reversible nanoparticle functionalization and construction of adaptive binary assemblies.

2D and 3D Ruthenium Nanoparticle Covalent Assemblies for Phenyl Acetylene Hydrogenation

“…[ 41 ] Surprisingly, even if colloidal Ru NP are usually highly efficient (selective) hydrogenation catalysts, [ 42 ] reports on the application of Ru NP for this specific catalytic reduction are relatively scarce. [ 16a,43 ] We recently evidenced that for 3D Ru NP assemblies produced from polymantane ligands, the Ru NP interparticle distance (steric effect) and electronic effects control the catalyst activity and selectivity. [ 15a ] Increase of activity was evidenced for electron rich Ru NP and/or for short interparticle distances.…”

“…[ 15 ] In these structures, the organic linker (or ligand) plays a fundamental role on constructing the NP network and defining NP chemical environment. [ 16 ] In that case, the reactant environment is significantly different since it is composed of an important number of catalytically active NP covalently linked by an organic molecule. The interparticle coupling effect has been demonstrated to significantly influence the optical properties of NP, [ 17 ] and is also able to affect their catalytic properties.…”

Rapidly Adaptive All‐covalent Nanoparticle Surface Engineering

“…On‐demand chemospecific transformations direct these dynamic covalent nanoparticle (DCNP) building blocks down different reaction pathways to access a variety of surface‐bound molecular structures, [2] manipulate and tune nanoparticle physicochemical properties,[ 2 , 3 ] and construct adaptive nanoparticle assemblies. [2b] Alternative adaptive functionalization strategies have typically relied on noncovalent interactions between environmentally sensitive oligonucleotides, [4] or artificial host‐guest systems, [5] which are by comparison relatively weak and often non‐specific. Conversely, permanent surface modifications are often achieved via ligand exchange, but this requires optimization for each different nanoparticle core material, can introduce surface defects, reconstructions or core size changes and produces mixed‐monolayer compositions that are governed by system‐specific nonlinear relationships.…”

“…The stability of covalently bonded systems, however, is accompanied by relatively slow exchange kinetics, which we have found to be further retarded by surface confinement when applied for nanoparticle surface engineering. [2b] We now report a “best‐of‐both‐worlds” DCNP synthon that addresses the shortcomings of both our previous technology and the alternative functionalization approaches. With this new DCNP design, rapid surface transformations are combined with a high degree of predictive control and the structural and functional stability of covalent bonds, enabling adaptive and environment‐responsive tuning of nanomaterial characteristics.…”

Photoacoustics for listening to metal nanoparticle super-aggregates

“…14 Non-covalent aggregation is a dynamic process that occurs in suitable solvents and covalent interconnected MNPs are also studied in the literature due to their intrinsic stability. [15][16][17] A common approach for the fabrication of functionalized nanoparticles is based on the reduction of metallic ions in solution in the presence of a reducing agent and of a ligand. Among others, thiol ligands show an intrinsic high covalent binding to metallic surfaces and bifunctional thiols can be used for the preparation of covalently interconnected nanoparticles.…”