Single-Chain Nanoparticles as Catalytic Nanoreactors

Abstract

The need for efficient, tailor-made catalysts has inspired chemists to fuse the design principles of natural enzymes with synthetic macromolecular architectures. A highly interesting pathway mimics a metallo-enzyme's tertiary structure via the target placement of metal-ions in a tailor-made polymeric framework, resulting in catalytically active single-chain nanoparticles. Initial studies reveal unusual and promising effects, regarding both new catalyst characteristics and a high impact on product formation. These multifunctional nanoreactors, constructed from simple folded polymer chains, will lead to advanced bioinspired catalytic systems. As found in enzymes, their impact lies specifically within the defined construction of a polymeric pocket around the catalytic active cores for substrate recognition.

Catalytically Active N‐Heterocyclic Carbene Release from Single‐Chain Nanoparticles Following a Thermolysis‐Driven Unfolding Strategy

“…In particular, a promising synthetic strategy inspired by nature has emerged to prepare unimolecular versatile nano‐objects referred to as single‐chain nanoparticles (SCNPs) . Indeed, these folded/collapsed soft nanostructures have gained increasing attention for the development of functional materials in the fields of nanomedicine, protein mimicry, and catalysis . In the catalysis field, the design of supported organometallic catalysts aims to emulate the unique features of (metallo)enzymes, such as structural complexity, compartmentalized functions, and site isolation .…”

“…Previous work in the area has typically focused on the formation of SCNPs by hydrogen or covalent bonding between supported orthogonal functions . More recently, coordination chemistry, where metals act as crosslinkers, inducing the single‐chain particle formation, has been developed . Surprisingly, the ability of Ag to trigger the single‐chain folding of catalytically active SCNPs remains unexploited despite the potential of Ag(I)‐NHC complexes to generate free NHCs and undergo transmetalation …”

A New Class of Materials: Sequence‐Defined Macromolecules and Their Emerging Applications

“…[30] We submit that the realm of bio-inspired catalysis is a key area to benefit from sequence-defined polymers, yet not before these become available in a similar structural variety of contemporary synthetic polymers. Contemporary synthetic technology allows only the generation of relatively short sequences in the majority of cases, certainly not within the realm of proteins or enzymes (typically exceeding 60 kDa).…”

Phenanthroline—A Versatile Ligand for Advanced Functional Polymeric Materials

“…In combination with metal‐ions, which provide additional functionality, for example, catalytic or photophysical characteristics, highly sophisticated metallo‐polymeric architectures can be realized . For instance, upon coordination to a polymer chain, metal‐centers can function as structure forming elements, resulting in enzyme‐like, three‐dimensional folded nano‐reactors . They are accessible by the integration of suitable ligand functionalities into the precursor polymer chains, which enable multiple ligand to metal‐coordination.…”