New routes to Cu(I)/Cu nanocatalysts for the multicomponent click synthesis of 1,2,3-triazoles

Nanoscale. 2013 Jan 7;5(1):342-50. doi: 10.1039/c2nr32570e. Epub 2012 Nov 20.

Abstract

An array of copper and copper-zinc based nanoparticles (NPs) have been fabricated employing a variety of polymeric capping agents. Analysis by TEM, XRPD and XPS suggests that by manipulating reagent, reductant and solvent conditions it is possible to achieve materials that are mono-/narrow disperse with mean particle sizes in the ≤10 nm regime. Oxidative stability in air is achieved for monometallic NPs using poly(methyl methacrylate) (PMMA) anti-agglomerant in conjunction with a variety of reducing conditions. In contrast, those encapsulated by either poly(1-vinylpyrrolidin-2-one) (PVP) or poly(4-vinylpyridine) (PVPy) rapidly show Cu(2)O formation, with all data suggesting progressive oxidation from Cu to Cu@Cu(2)O core-shell structure and finally Cu(2)O. Bimetallic copper-zinc systems, reveal metal segregation and the formation of Cu(2)O and ZnO. Catalysts have been screened in the synthesis of 1,2,3-triazoles through multicomponent azide-alkyne 1,3-dipolar cycloaddition. Whereas PMMA- and PVPy-coating results in reduced catalytic activity, those protected by PVP are highly active, with quantitative triazole syntheses achieved at room temperature and with catalyst loadings of 0.03 mol% metal for Cu and CuZn systems prepared using NaH(2)PO(2), N(2)H(4) or NaBH(4) reductants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Click Chemistry / methods*
  • Copper / chemistry*
  • Crystallization / methods*
  • Macromolecular Substances / chemistry
  • Materials Testing
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure*
  • Molecular Conformation
  • Particle Size
  • Surface Properties
  • Triazoles / chemistry*

Substances

  • Macromolecular Substances
  • Triazoles
  • Copper