Abstract
The exceptional stability of thiolate-protected Au25 clusters, [Au25(SR)18]-, arises from the closure of superatomic electron shells, leading to a noble-gas-like 8-electron configuration (1S21P6). Here we present that replacing the core Au atom with Pd or Pt results in stable [MAu24(SR)18]0 clusters (M = Pd, Pt) having a superatomic 6-electron configuration (1S21P4). Voltammetric studies of [PdAu24(SR)18]0 and [PtAu24(SR)18]0 reveal that the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of these clusters are 0.32 and 0.29 eV, respectively, indicating their electronic structures are drastically altered upon doping of the foreign metal. Density functional investigations confirm that the HOMO-LUMO gaps of these clusters are indeed smaller, respectively 0.33 and 0.32 eV, than that of [Au25(SR)18]- (1.35 eV). Analysis of the optimized geometries for the 6-electron [MAu24(SR)18]0 clusters shows that the MAu12 core is slightly flattened to yield an oblate ellipsoid. The drastically decreased HOMO-LUMO gaps observed are therefore the result of Jahn-Teller-like distortion of the 6-electron [MAu24(SR)18]0 clusters, accompanying splitting of the 1P orbitals. These clusters become 8-electron [MAu24(SR)18]2- clusters upon electronic charging, demonstrating reversible interconversion between the 6-electron and 8-electron configurations of MAu24(SR)18.
| Original language | English |
|---|---|
| Pages (from-to) | 10833-10840 |
| Number of pages | 8 |
| Journal | Journal of the American Chemical Society |
| Volume | 137 |
| Issue number | 33 |
| DOIs | |
| Publication status | Published - 2015 Jul 29 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry
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Interconversion between Superatomic 6-Electron and 8-Electron Configurations of M@Au24(SR)18 Clusters (M = Pd, Pt). / Kwak, Kyuju; Tang, Qing; Kim, Minseok; Jiang, De En; Lee, Dongil.
In: Journal of the American Chemical Society, Vol. 137, No. 33, 29.07.2015, p. 10833-10840.Research output: Contribution to journal › Article
TY - JOUR
T1 - Interconversion between Superatomic 6-Electron and 8-Electron Configurations of M@Au24(SR)18 Clusters (M = Pd, Pt)
AU - Kwak, Kyuju
AU - Tang, Qing
AU - Kim, Minseok
AU - Jiang, De En
AU - Lee, Dongil
PY - 2015/7/29
Y1 - 2015/7/29
N2 - The exceptional stability of thiolate-protected Au25 clusters, [Au25(SR)18]-, arises from the closure of superatomic electron shells, leading to a noble-gas-like 8-electron configuration (1S21P6). Here we present that replacing the core Au atom with Pd or Pt results in stable [MAu24(SR)18]0 clusters (M = Pd, Pt) having a superatomic 6-electron configuration (1S21P4). Voltammetric studies of [PdAu24(SR)18]0 and [PtAu24(SR)18]0 reveal that the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of these clusters are 0.32 and 0.29 eV, respectively, indicating their electronic structures are drastically altered upon doping of the foreign metal. Density functional investigations confirm that the HOMO-LUMO gaps of these clusters are indeed smaller, respectively 0.33 and 0.32 eV, than that of [Au25(SR)18]- (1.35 eV). Analysis of the optimized geometries for the 6-electron [MAu24(SR)18]0 clusters shows that the MAu12 core is slightly flattened to yield an oblate ellipsoid. The drastically decreased HOMO-LUMO gaps observed are therefore the result of Jahn-Teller-like distortion of the 6-electron [MAu24(SR)18]0 clusters, accompanying splitting of the 1P orbitals. These clusters become 8-electron [MAu24(SR)18]2- clusters upon electronic charging, demonstrating reversible interconversion between the 6-electron and 8-electron configurations of MAu24(SR)18.
AB - The exceptional stability of thiolate-protected Au25 clusters, [Au25(SR)18]-, arises from the closure of superatomic electron shells, leading to a noble-gas-like 8-electron configuration (1S21P6). Here we present that replacing the core Au atom with Pd or Pt results in stable [MAu24(SR)18]0 clusters (M = Pd, Pt) having a superatomic 6-electron configuration (1S21P4). Voltammetric studies of [PdAu24(SR)18]0 and [PtAu24(SR)18]0 reveal that the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of these clusters are 0.32 and 0.29 eV, respectively, indicating their electronic structures are drastically altered upon doping of the foreign metal. Density functional investigations confirm that the HOMO-LUMO gaps of these clusters are indeed smaller, respectively 0.33 and 0.32 eV, than that of [Au25(SR)18]- (1.35 eV). Analysis of the optimized geometries for the 6-electron [MAu24(SR)18]0 clusters shows that the MAu12 core is slightly flattened to yield an oblate ellipsoid. The drastically decreased HOMO-LUMO gaps observed are therefore the result of Jahn-Teller-like distortion of the 6-electron [MAu24(SR)18]0 clusters, accompanying splitting of the 1P orbitals. These clusters become 8-electron [MAu24(SR)18]2- clusters upon electronic charging, demonstrating reversible interconversion between the 6-electron and 8-electron configurations of MAu24(SR)18.
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U2 - 10.1021/jacs.5b06946
DO - 10.1021/jacs.5b06946
M3 - Article
AN - SCOPUS:84941711149
VL - 137
SP - 10833
EP - 10840
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 33
ER -