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US-12623250-B2 - Carbene-functionalized composite materials

US12623250B2US 12623250 B2US12623250 B2US 12623250B2US-12623250-B2

Abstract

The present application provides stable, carbene-functionalized composite materials, and methods and uses thereof. These carbene-functionalized composite materials comprise a material having a metal surface, and a carbene monolayer that is uniform, contaminant-free (metal oxide, etc), and more stable than thiol-functionalized monolayers. Uses of such carbene-functionalized composite materials include semi-conducting materials, microelectronic devices, drug delivery or sensing applications.

Inventors

  • Cathleen M. Crudden
  • J. Hugh Horton
  • Olena V. Zenkina
  • Iraklii I. Ebralidze
  • Christene Anne Smith

Assignees

  • QUEEN'S UNIVERSITY AT KINGSTON

Dates

Publication Date
20260512
Application Date
20231027

Claims (7)

  1. 1 . A carbene-functionalized composite, comprising: 1,3-dihydro-1,3-bisisopropyl-2H-benzimidazol-2-ylidene carbene coating on a metal surface, wherein the metal is selected from the group consisting of gold, palladium, platinum, ruthenium, rhodium, iridium, and any combination thereof, and wherein the 1,3-dihydro-1,3-bisisopropyl-2H-benzimidazol-2-ylidene carbene interacts with the metal surface to form a densely packed carbene monolayer coating that exhibits long-range ordering and is thermally stable at 100° C. for 24 hours, wherein the carbene monolayer comprises ≤5% contamination, and wherein the metal surface is selected from the group consisting of bulk metal, solid metal, atomically ordered metal surface, metal film, metal sheet, and metal layer, and is not a nanoparticle.
  2. 2 . The composite of claim 1 , further comprising a support comprised of mica, alumina, silica, titania, silicon, glass, indium tin oxide, or any combination thereof.
  3. 3 . The composite of claim 1 , wherein the metal surface is a metal chip.
  4. 4 . The composite of claim 1 , wherein the composite is a surface plasmon resonance (SPR) detector chip.
  5. 5 . The composite of claim 4 , wherein the SPR detector chip comprises gold, palladium, platinum, ruthenium, rhodium, iridium, or any combination thereof.
  6. 6 . The composite of claim 1 , wherein the metal surface comprises an alloy.
  7. 7 . The composite of claim 1 , further comprising a non-metal surface.

Description

RELATED APPLICATIONS This application claims the benefit of the filing dates of U.S. Provisional Patent Application No. 61/867,466, filed on Aug. 19, 2013, and U.S. Provisional Patent Application No. 62/018,782, filed on Jun. 30, 2014, the contents of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION The present application pertains to the field of materials science. More particularly, the present application relates to carbene-functionalized composite materials. BACKGROUND Self-assembled monolayers (SAMs) on metals such as gold have potential application in sensing, electrochemistry, drug delivery, surface protection, microelectronics and microelectromechanical systems, among others [R. G. Nuzzo, et al. J. Am. Chem. Soc. 105, 4481 (1983); B. D. Gates, et al. Chem. Rev. 105, 1171 (2005); J. C. Love, et al. Chem. Rev. 105, 1103 (2005); U. Drechsler, et al. Chem.-Eur. J. 10, 5570 (2004)]. Since a discovery of sulfur-based SAMs on gold [C. D. Bain et al. J. Am. Chem. Soc. 111, 321 (1989)], suitable alternatives for these ligands have not been found, despite the thiol-based SAMs' oxidative and thermal instability on gold being a significant impediment to their widespread use [C. Vericat, et al. Chem. Soc. Rev. 39, 1805 (2010)]. Thiol-based SAMs are stable when stored in ultra high vacuum in an absence of light [J. Noh, et al. J. Phys. Chem. B 110, 2793 (2006)], however degradation has been observed after as little as one to two weeks at room temperature in air [C. Vericat, et al. J. Phys. Condens. Matter 20, 184004 (2008); Y. Li, et al. J. Am. Chem. Soc. 114, 2428 (1992); M. H. Schoenfisch, et al. J. Am. Chem. Soc. 120, 4501 (1998); J. B. Schlenoff, et al. J. Am. Chem. Soc. 117, 12528 (1995)]. Improvements in stability can be accomplished by changing the gold surface's nature [C. Vericat, et al. J. Phys. Condens. Matter 20, 184004 (2008)], by addition of additives [G. Yang, et al. Langmuir 20, 3995 (2004)], or through use of multi-dentate thio-adsorbates [P. Chinwangso, A. C. Jamison, T. R. Lee, Accounts of Chemical Research, 44, 511 (2011)]. Phosphine-based ligands have also been examined, but offer weaker bonds to a surface [A. D. Jewell, et al. Phys. Rev. B 82, 205401 (2010)]. Carbon-based ligands known as N-heterocyclic carbenes (NHCs) have played a role in the field of transition metal complexes [W. A. Herrmann, Angew. Chem. Int. Ed. 41, 1290 (2002); E. Peris, et al. Coord. Chem. Rev. 248, 2239 (2004)]. These ligands are part of catalysts such as the Grubbs second generation metathesis catalyst [R. M. Thomas, et al. Organometallics 30, 6713 (2011)], and NHC-based cross-coupling catalysts [E. A. B Kantchev, et al. Angew. Chem. Int. Ed. 46, 2768 (2007)]. Unlike most carbenes, which are reactive with limited stability, NHCs typically have one or two heteroatoms adjacent to a carbene carbon [A. Igau, et al. J. Am. Chem. Soc. 110, 6463 (1988); A. J. Arduengo, et al. J. Am. Chem. Soc. 113, 361 (1991)]. These heteroatoms increase NHCs' stability such that they can usually be prepared on a gram scale [M. Niehues, et al. Organometallics 21, 2905 (2002)], crystallized [A. J. Arduengo, R. L. Harlow, M. Kline, J. Am. Chem. Soc. 113, 361 (1991)], distilled [M. Niehues, et al. Organometallics 21, 2905 (2002)], and stored for longer periods of time [4 years, when stored under N2 in a freezer]. An Au—NHC bond is estimated to be on an order of 90 KJ/mol stronger than a corresponding Au-phosphine bond, and twice as strong as metal sulfide bonds in molecular complexes [P. Pyykkö, et al. Chem. Asian J. 1, 623 (2006)]. As such, NHCs have potential to be valuable ligands for protecting and functionalizing gold and other metal surfaces. Application of these carbenes in materials science, and other fields outside of homogeneous catalysis, has been limited [L. Mercs, et al. Chem. Soc. Rev. 39, 1903 (2010)]. The above information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention. SUMMARY OF THE INVENTION An aspect of the application is to provide carbene-functionalized composite materials and methods of manufacture thereof. In accordance with one aspect, there is provided a carbene-functionalized composite material, comprising a carbene monolayer, and a material having at least a metal surface, wherein the carbene monolayer interacts with the metal surface and is stable, uniform, and/or substantially free of contamination. In one embodiment, the carbene monolayer comprises ≤5%, or ≤2% contamination. In accordance with another embodiment, the carbene monolayer comprises one or more carbenes of formula I wherein: n is an integer from 1 to 8, or from 1 to 4;m is an integer from 0 to 4;A is absent, an aliphatic cycle, a heterocycle, an aromatic ring, a fused aromatic