Research ArticleChemistry

Ligand effects in catalysis by atomically precise gold nanoclusters

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Science Advances  06 Oct 2017:
Vol. 3, no. 10, e1701823
DOI: 10.1126/sciadv.1701823
  • Fig. 1 Mass spectra of the Au38 nanoclusters.

    Inset: Measured (black trace) and simulated (red trace) isotopic patterns. (A) [Au38(PhC≡C)20(Ph3P)4]2+ in 1. (B) [Au38(m-MBT)20(Ph3P)4]2+ in 2.

  • Fig. 2 Structure of the Au38 dications.

    (A) [Au38(PhC≡C)20(Ph3P)4]2+ in 1. (B) [Au38(m-MBT)20(Ph3P)4]2+ in 2.

  • Fig. 3 Anatomy of the Au38 kernel structure.

    (A) Au34 kernel attached with four PhC≡C–Au–C≡CPh staple motifs. (B) Au34 kernel with 12 bridging PhC≡C ligands. (C) Au34 (fcc type) kernel in Au38. (D) Model of interpenetrated bicuboctahedral Au20. (E) Au34 kernel attached with four RS–Au–SR staple motifs (SR = m-MBT). Orange/green/blue, Au atoms; yellow, S atoms; gray, C atoms.

  • Fig. 4 Optical absorption spectra of Au38 in CH2Cl2 and their TEM images.

    (A) TEM image of 1. (B) TEM image of 2. Black and red lines represent 1 and 2, respectively.

  • Fig. 5 UV-vis spectra and ESI-MS of Au38 in CH2Cl2.

    (A and C) UV-vis spectra and ESI-MS of 1. (B and D) UV-vis spectra and ESI-MS of 2. Black and red lines represent before and after thermal treatments, respectively.

  • Fig. 6 Activities of TiO2 and 1/TiO2 for the semihydrogenation of alkynes.

    (A) The substrate is ethynylbenzene [H2 (10 bar)]. (B) The substrate is diphenylacetylene [H2 (20 bar)].

  • Table 1 Semihydrogenation of terminal* and internal alkynes on Au38/TiO2 catalyst.
    Embedded Image
    EntryCatalystR1R2Conversion (%)Selectivity (%)
    11PhH100100
    2PhC2H4H100100
    3PhPh10093
    4Ph4-Br-Ph9794
    5PhCH39794
    62PhH1.6
    7PhC2H4H1.4
    8PhPh1.7
    9Ph4-Br-Ph<1
    10PhCH3<1

    *Reaction conditions: 80 mg of Au38 [0.4 weight % (wt %)]/TiO2 catalyst, 0.2 mmol of alkynes, 0.4 mmol of pyridine, 1.0 ml of EtOH/H2O (10:1, v/v), 80°C, H2 (10 bar), 15 hours.

    †Reaction conditions: 80 mg of Au38 (0.4 wt %)/TiO2 catalyst, 0.2 mmol of alkynes, 0.4 of mmol pyridine, 1.0 ml of EtOH/H2O (10:1, v/v), 110°C, H2 (20 bar), 20 hours.

    ‡The conversion and stereoselectivity for Z-alkenes were determined by 1H NMR.

    Supplementary Materials

    • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/10/e1701823/DC1

      Physical measurements

      Synthesis

      Characterization

      fig. S1. TGA of 1 and 2.

      fig. S2. XPS spectra of Au 4f in 1 and 2.

      fig. S3. Fourier transform infrared spectrum of 1.

      fig. S4. The Au34 kernel in Au38.

      fig. S5. The stability check of 1 and 2 in CH2Cl2 solution.

      fig. S6. 31P NMR spectra of 1 and 2 in CD2Cl2.

      fig. S7. TEM images of Au38 catalyst at different periods.

      fig. S8. 1H NMR spectra of the catalytic products.

      fig. S9. TEM images of 1/TiO2 and 2/TiO2 catalysts treated at different temperatures.

      fig. S10. The anion exchange of 2 with KSO3CF3 in CH2Cl2 solution.

      fig. S11. The relationship between reaction time and conversion and selectivity in the semihydrogenation of alkynes.

      table S1. The catalytic performance of Au38 (0.4 wt %)/TiO2 catalyst pretreated at different temperatures in the semihydrogenation of diphenylacetylene.

      CIF File

      References (4850)

    • Supplementary Materials

      This PDF file includes:

      • Physical measurements
      • Synthesis
      • Characterization
      • fig. S1. TGA of 1 and 2.
      • fig. S2. XPS spectra of Au 4f in 1 and 2.
      • fig. S3. Fourier transform infrared spectrum of 1.
      • fig. S4. The Au34 kernel in Au38.
      • fig. S5. The stability check of 1 and 2 in CH2Cl2 solution.
      • fig. S6. 31P NMR spectra of 1 and 2 in CD2Cl2.
      • fig. S7. TEM images of Au38 catalyst at different periods.
      • fig. S8. 1H NMR spectra of the catalytic products.
      • fig. S9. TEM images of 1/TiO2 and 2/TiO2 catalysts treated at different temperatures.
      • fig. S10. The anion exchange of 2 with KSO3CF3 in CH2Cl2 solution.
      • fig. S11. The relationship between reaction time and conversion and selectivity in the semihydrogenation of alkynes.
      • table S1. The catalytic performance of Au38 (0.4 wt %)/TiO2 catalyst pretreated at different temperatures in the semihydrogenation of diphenylacetylene.
      • References (48–50)

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      Other Supplementary Material for this manuscript includes the following:

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