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A facile methodology to prepare N-heterocyclic carbene (NHC)-terminated polymers as surface ligands to functionalize gold nanoparticles (AuNPs) is reported. Our method highlights a mild, aerobic synthesis of NHC-functionalized polymers and a simple ligand exchange approach towards surface modification of AuNPs prepared in aqueous solution. Two methods, including end-group functionalization of halogen-ended polymers from a conventional atom transfer radical polymerization (ATRP) and post-polymerization functionalization of imidazole-containing polymers using imidazole-containing ATRP initiator, have been investigated to prepare imidazolium-ended polymers. Using a one-step, oxygen and moisture tolerant procedure, the polymer–NHC–Cu( i ) species can be synthesized from imidazolium-ended polymers and readily bind to citrate-capped AuNPs likely through transmetalation, yielding robust polymer-stabilized AuNPs. Our synthetic method significantly simplifies the preparation and use of polymer–NHC ligands for surface functionalization of metal NPs. Our methodology is general and potentially applicable to any polymers prepared by ATRP to functionalize metal NPs via NHC–metal coordination; therefore, it will likely broaden the applications of polymer–NHC ligands for metal nanoparticles in the fields of catalysis and nanomedicine.
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This content will become publicly available on April 4, 2026
N‐Heterocyclic Carbene‐Based Copolymers for Templated Synthesis and Stabilization of Gold Nanoparticles
Abstract Surface functionalization and colloidal stability are pivotal for numerous applications of gold nanoparticles (Au‐NPs). Over the past decade, N‐heterocyclic carbenes (NHCs) have emerged as promising ligands for stabilizing Au‐NPs owing to their ease of synthesis, structural diversity, and strong metal‐ligand bonds. Here, we introduce new Au(I)–NHCcopolymer scaffolds as precursors to multidentate NHC‐protected Au‐NPs. Ring‐opening metathesis copolymerization of a norbornene‐appended Au(I)−NHC complex with another functionalized norbornene comonomer provides NHC–Au(I) copolymers with modular compositions and structures. Upon reduction, these copolymers yield multidentate polyNHC‐coated Au‐NPs with varied properties and corona functionalities dictated by the secondary monomer. These nanoparticles exhibit excellent size homogeneity and stability against aggregation in various buffers, cell culture media, and under exposure to electrolytes, oxidants, and exogenous thiols over extended periods. Moreover, we demonstrate post‐synthetic surface functionalization reactions of polyNHC−Au‐NPs while maintaining colloidal stability, highlighting their robustness and potential for applications such as bioconjugation. Overall, these findings underscore the potential of ROMP‐derived NHC‐containing copolymers as highly tunable and versatile multidentate ligands that may be suitable for other inorganic colloids and flat surfaces.
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- Award ID(s):
- 2411155
- PAR ID:
- 10596369
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 31
- Issue:
- 20
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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