TY - JOUR
T1 - Probing the Structural Evolution of Gold-Aluminum Bimetallic Clusters (Au2Aln-, n = 3-11) Using Photoelectron Spectroscopy and Theoretical Calculations
AU - Khetrapal, Navneet Singh
AU - Jian, Tian
AU - Lopez, Gary V.
AU - Pande, Seema
AU - Wang, Lai Sheng
AU - Zeng, Xiao Cheng
N1 - Funding Information:
The experiment done at Brown University was supported by the National Science Foundation (CHE-1263745 to L.S.W.). X.C.Z. was supported by a grant from Nebraska Center for Energy Sciences Research. The calculations were done in the Holland Computing Center at University of Nebraska Lincoln. T. J. thanks Dr. Wei-Li Li for earlier experimental assistance.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/8/24
Y1 - 2017/8/24
N2 - We report a combined photoelectron spectroscopy and theoretical study of the structural evolution of aluminum cluster anions doped with two gold atoms, Au2Aln- (n = 3-11). Well-resolved photoelectron spectra have been obtained at several photon energies and are used to compare with theoretical calculations to elucidate the structures of the bimetallic clusters. Global minima of the Au2Aln- clusters were searched using the basin-hopping method combined with density functional theory calculations. Vertical detachment energies were computed for the low-lying isomers with the inclusion of spin-orbit effects and were used to generate simulated photoelectron spectra. Au2Al2- was previously found to exhibit a tetrahedral structure, whereas Au2Al3- is found currently to be planar. Beyond n = 3, the global minima of Au2Aln- are dominated by three-dimensional structures. A robust square-bipyramidal Al6 motif is observed for n = 6-9, leading to a highly stable tubular-like global minimum for Au2Al9-. Compact three-dimensional structures are observed for n = 10 and 11. Except for Au2Al4-, Au2Al6-, and Au2Al7-, the two gold atoms are separated in these digold-atom-doped aluminum clusters due to the strong Au-Al interactions.
AB - We report a combined photoelectron spectroscopy and theoretical study of the structural evolution of aluminum cluster anions doped with two gold atoms, Au2Aln- (n = 3-11). Well-resolved photoelectron spectra have been obtained at several photon energies and are used to compare with theoretical calculations to elucidate the structures of the bimetallic clusters. Global minima of the Au2Aln- clusters were searched using the basin-hopping method combined with density functional theory calculations. Vertical detachment energies were computed for the low-lying isomers with the inclusion of spin-orbit effects and were used to generate simulated photoelectron spectra. Au2Al2- was previously found to exhibit a tetrahedral structure, whereas Au2Al3- is found currently to be planar. Beyond n = 3, the global minima of Au2Aln- are dominated by three-dimensional structures. A robust square-bipyramidal Al6 motif is observed for n = 6-9, leading to a highly stable tubular-like global minimum for Au2Al9-. Compact three-dimensional structures are observed for n = 10 and 11. Except for Au2Al4-, Au2Al6-, and Au2Al7-, the two gold atoms are separated in these digold-atom-doped aluminum clusters due to the strong Au-Al interactions.
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U2 - 10.1021/acs.jpcc.7b04997
DO - 10.1021/acs.jpcc.7b04997
M3 - Article
AN - SCOPUS:85028354923
SN - 1932-7447
VL - 121
SP - 18234
EP - 18243
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 33
ER -