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Title: Novel polyoxoanion- and Bu{sub 4}N{sup +} stabilized, isolable, and redissolvable, 20-30-A Ir {sub approximately 300-900} nanoclusters. The kinetically controlled synthesis, characterization, and mechanism of formation or organic solvent-soluble, reproducible size, and reproducible catalytic activity metal nanoclusters

Abstract

Nearly monodispersed 30 {+-} 4 A Ir {sub approximately 900} nanoclusters have been prepared by hydrogen reduction of a polyoxoanion-supported Ir(I) complex, (Bu{sub 4}N){sub 5}Na{sub 3}[(1,5-COD)Ir-P{sub 2}W{sub 15}Nb{sub 3}O{sub 62}] (1,5-COD is 1,5-cycloctadiene), in acetone solution. The Ir {sub approximately 900} nanoclusters can be isolated as a black powder and redissolved in acetone or CH{sub 3}CN to give a stable, amber solution. Extensive characterizations of the Ir {sub approximately 900} nanoclusters have been made by means of TEM, electron diffraction, electrophoresis, ultracentrifugation solution molecular-weight measurements, fast-atom bombardment mass spectroscopy, elemental analysis, and IR and UV-vis spectroscopy; their average chemical composition is [Ir(O) approximately 900 (P{sub 4}W{sub 30}Nb{sub 6}O{sub 123}{sup 16-}) {sub approximately 60}] (Bu{sub 4}N) {sub approximately 660} Na {sub approximately 300}, in which the polyoxoanion is found to be in its oxidized and Nb-O-Nb bridged aggregate form, P{sub 4}W{sub 30}Nb{sub 6}O{sub 123}{sup 16-}. Electron diffraction studies show that the nanoclusters consist of cubic close-packed (ccp) Ir metal cores; electrophoresis and other techniques establish that the nanoclusters are stabilized in solution by the adsorption of the polyoxoanions on their outer surfaces. Smaller, ca. 20-A Ir-300 nanoclusters have also been reproducibly prepared and characterized from (Bu{sub 4}N){sub 5}Na{sub 3}[(1,5-COD)Ir-P{sub 2}W{sub 15}Nb{submore » 3}O{sub 62}] and from (Bu{sub 4}N){sub 4-} Na{sub 2}[(1,5-COD)Ir-SiW{sub 9}Nb{sub 3}O{sub 40}] during the catalytic hydrogenation of cyclohexene. 58 refs., 13 figs.« less

Authors:
;  [1]
  1. Colorado State Univ., Fort Collins, CO (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
102779
DOE Contract Number:  
FG06-89ER13998
Resource Type:
Journal Article
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 116; Journal Issue: 18; Other Information: PBD: 7 Sep 1994
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; NIOBIUM COMPLEXES; REDUCTION; IRIDIUM COMPLEXES; SOLID CLUSTERS; SYNTHESIS; CYCLOALKENES; HYDROGENATION; HYDROGEN; CATALYSIS; ACETONE; ACETONITRILE; IRIDIUM; TRANSMISSION ELECTRON MICROSCOPY; ELECTRON DIFFRACTION; ELECTROPHORESIS; ULTRACENTRIFUGATION; MASS SPECTROSCOPY; INFRARED SPECTRA; ULTRAVIOLET SPECTRA

Citation Formats

Lin, Y, and Finke, R G. Novel polyoxoanion- and Bu{sub 4}N{sup +} stabilized, isolable, and redissolvable, 20-30-A Ir {sub approximately 300-900} nanoclusters. The kinetically controlled synthesis, characterization, and mechanism of formation or organic solvent-soluble, reproducible size, and reproducible catalytic activity metal nanoclusters. United States: N. p., 1994. Web. doi:10.1021/ja00097a047.
Lin, Y, & Finke, R G. Novel polyoxoanion- and Bu{sub 4}N{sup +} stabilized, isolable, and redissolvable, 20-30-A Ir {sub approximately 300-900} nanoclusters. The kinetically controlled synthesis, characterization, and mechanism of formation or organic solvent-soluble, reproducible size, and reproducible catalytic activity metal nanoclusters. United States. https://doi.org/10.1021/ja00097a047
Lin, Y, and Finke, R G. 1994. "Novel polyoxoanion- and Bu{sub 4}N{sup +} stabilized, isolable, and redissolvable, 20-30-A Ir {sub approximately 300-900} nanoclusters. The kinetically controlled synthesis, characterization, and mechanism of formation or organic solvent-soluble, reproducible size, and reproducible catalytic activity metal nanoclusters". United States. https://doi.org/10.1021/ja00097a047.
@article{osti_102779,
title = {Novel polyoxoanion- and Bu{sub 4}N{sup +} stabilized, isolable, and redissolvable, 20-30-A Ir {sub approximately 300-900} nanoclusters. The kinetically controlled synthesis, characterization, and mechanism of formation or organic solvent-soluble, reproducible size, and reproducible catalytic activity metal nanoclusters},
author = {Lin, Y and Finke, R G},
abstractNote = {Nearly monodispersed 30 {+-} 4 A Ir {sub approximately 900} nanoclusters have been prepared by hydrogen reduction of a polyoxoanion-supported Ir(I) complex, (Bu{sub 4}N){sub 5}Na{sub 3}[(1,5-COD)Ir-P{sub 2}W{sub 15}Nb{sub 3}O{sub 62}] (1,5-COD is 1,5-cycloctadiene), in acetone solution. The Ir {sub approximately 900} nanoclusters can be isolated as a black powder and redissolved in acetone or CH{sub 3}CN to give a stable, amber solution. Extensive characterizations of the Ir {sub approximately 900} nanoclusters have been made by means of TEM, electron diffraction, electrophoresis, ultracentrifugation solution molecular-weight measurements, fast-atom bombardment mass spectroscopy, elemental analysis, and IR and UV-vis spectroscopy; their average chemical composition is [Ir(O) approximately 900 (P{sub 4}W{sub 30}Nb{sub 6}O{sub 123}{sup 16-}) {sub approximately 60}] (Bu{sub 4}N) {sub approximately 660} Na {sub approximately 300}, in which the polyoxoanion is found to be in its oxidized and Nb-O-Nb bridged aggregate form, P{sub 4}W{sub 30}Nb{sub 6}O{sub 123}{sup 16-}. Electron diffraction studies show that the nanoclusters consist of cubic close-packed (ccp) Ir metal cores; electrophoresis and other techniques establish that the nanoclusters are stabilized in solution by the adsorption of the polyoxoanions on their outer surfaces. Smaller, ca. 20-A Ir-300 nanoclusters have also been reproducibly prepared and characterized from (Bu{sub 4}N){sub 5}Na{sub 3}[(1,5-COD)Ir-P{sub 2}W{sub 15}Nb{sub 3}O{sub 62}] and from (Bu{sub 4}N){sub 4-} Na{sub 2}[(1,5-COD)Ir-SiW{sub 9}Nb{sub 3}O{sub 40}] during the catalytic hydrogenation of cyclohexene. 58 refs., 13 figs.},
doi = {10.1021/ja00097a047},
url = {https://www.osti.gov/biblio/102779}, journal = {Journal of the American Chemical Society},
number = 18,
volume = 116,
place = {United States},
year = {Wed Sep 07 00:00:00 EDT 1994},
month = {Wed Sep 07 00:00:00 EDT 1994}
}