Advanced search
2 files | 2.44 MB Add to list

Insights into the ligand shell, coordination mode, and reactivity of carboxylic acid capped metal oxide nanocrystals

(2016) CHEMPLUSCHEM. 81(11). p.1216-1223
Author
Organization
Abstract
A detailed knowledge of surface chemistry is necessary to bridge the gap between nanocrystal synthesis and applications. Although it has been proposed that carboxylic acids bind to metal oxides in a dissociative NC(X)(2) binding motif, this surface chemistry was inferred from indirect evidence on HfO2 nanocrystals (NCs). Here, a more detailed picture of the coordination mode of carboxylate ligands on HfO2 and ZrO2 NC surfaces is shown by direct observation through solid-state NMR techniques. Surface-adsorbed protons are clearly distinguished and two coordination modes of the carboxylic acid are noted: chelating and bridging. It is also found that secondary ligands penetrate the ligand shell and have the same orientation with respect to the surface as the primary ligands, indicating that the ionic or hydrogen-bonding interactions with the surface are more important than the van der Waals interactions with neighboring ligands. During ligand exchange with amines, the chelating carboxylate is removed preferentially. Finally, it is shown that the HfO2 and ZrO2 NCs catalyze imine formation from acetone and oleylamine. Together with the previously reported catalytic activity of HfO2, these results put colloidal metal oxide nanocrystals squarely in the focus of catalysis research.
Keywords
carboxylate ligands, nanocatalysis, nanoparticles, NMR spectroscopy, surface chemistry, QUANTUM-DOT SOLIDS, ONE-POT SYNTHESIS, SURFACE-CHEMISTRY, RUTHENIUM NANOPARTICLES, COLLOIDAL NANOCRYSTALS, HFO2 NANOPARTICLES, BUILDING-BLOCKS, STATE NMR, BINDING, EXCHANGE

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 1.26 MB
  • Insights in the ligand shell, the coordination mode and reactivity of carboxylic acid capped metal oxide nanocrystals. .pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 1.18 MB

Citation

Please use this url to cite or link to this publication:

MLA
De Roo, Jonathan et al. “Insights into the Ligand Shell, Coordination Mode, and Reactivity of Carboxylic Acid Capped Metal Oxide Nanocrystals.” CHEMPLUSCHEM 81.11 (2016): 1216–1223. Print.
APA
De Roo, J., Baquero, E. A., Coppel, Y., De Keukeleere, K., Van Driessche, I., Nayral, C., Hens, Z., et al. (2016). Insights into the ligand shell, coordination mode, and reactivity of carboxylic acid capped metal oxide nanocrystals. CHEMPLUSCHEM, 81(11), 1216–1223.
Chicago author-date
De Roo, Jonathan, Edwin A Baquero, Yannick Coppel, Katrien De Keukeleere, Isabel Van Driessche, Céline Nayral, Zeger Hens, and Fabien Delpech. 2016. “Insights into the Ligand Shell, Coordination Mode, and Reactivity of Carboxylic Acid Capped Metal Oxide Nanocrystals.” Chempluschem 81 (11): 1216–1223.
Chicago author-date (all authors)
De Roo, Jonathan, Edwin A Baquero, Yannick Coppel, Katrien De Keukeleere, Isabel Van Driessche, Céline Nayral, Zeger Hens, and Fabien Delpech. 2016. “Insights into the Ligand Shell, Coordination Mode, and Reactivity of Carboxylic Acid Capped Metal Oxide Nanocrystals.” Chempluschem 81 (11): 1216–1223.
Vancouver
1.
De Roo J, Baquero EA, Coppel Y, De Keukeleere K, Van Driessche I, Nayral C, et al. Insights into the ligand shell, coordination mode, and reactivity of carboxylic acid capped metal oxide nanocrystals. CHEMPLUSCHEM. 2016;81(11):1216–23.
IEEE
[1]
J. De Roo et al., “Insights into the ligand shell, coordination mode, and reactivity of carboxylic acid capped metal oxide nanocrystals,” CHEMPLUSCHEM, vol. 81, no. 11, pp. 1216–1223, 2016.
@article{8502430,
  abstract     = {A detailed knowledge of surface chemistry is necessary to bridge the gap between nanocrystal synthesis and applications. Although it has been proposed that carboxylic acids bind to metal oxides in a dissociative NC(X)(2) binding motif, this surface chemistry was inferred from indirect evidence on HfO2 nanocrystals (NCs). Here, a more detailed picture of the coordination mode of carboxylate ligands on HfO2 and ZrO2 NC surfaces is shown by direct observation through solid-state NMR techniques. Surface-adsorbed protons are clearly distinguished and two coordination modes of the carboxylic acid are noted: chelating and bridging. It is also found that secondary ligands penetrate the ligand shell and have the same orientation with respect to the surface as the primary ligands, indicating that the ionic or hydrogen-bonding interactions with the surface are more important than the van der Waals interactions with neighboring ligands. During ligand exchange with amines, the chelating carboxylate is removed preferentially. Finally, it is shown that the HfO2 and ZrO2 NCs catalyze imine formation from acetone and oleylamine. Together with the previously reported catalytic activity of HfO2, these results put colloidal metal oxide nanocrystals squarely in the focus of catalysis research.},
  author       = {De Roo, Jonathan and Baquero, Edwin A and Coppel, Yannick and De Keukeleere, Katrien and Van Driessche, Isabel and Nayral, Céline and Hens, Zeger and Delpech, Fabien},
  issn         = {2192-6506},
  journal      = {CHEMPLUSCHEM},
  keywords     = {carboxylate ligands,nanocatalysis,nanoparticles,NMR spectroscopy,surface chemistry,QUANTUM-DOT SOLIDS,ONE-POT SYNTHESIS,SURFACE-CHEMISTRY,RUTHENIUM NANOPARTICLES,COLLOIDAL NANOCRYSTALS,HFO2 NANOPARTICLES,BUILDING-BLOCKS,STATE NMR,BINDING,EXCHANGE},
  language     = {eng},
  number       = {11},
  pages        = {1216--1223},
  title        = {Insights into the ligand shell, coordination mode, and reactivity of carboxylic acid capped metal oxide nanocrystals},
  url          = {http://dx.doi.org/10.1002/cplu.201600372},
  volume       = {81},
  year         = {2016},
}

Altmetric
View in Altmetric
Web of Science
Times cited: