A revisit to the structure of Au-20(SCH2CH2Ph)(16): a cubic nanocrystal-like gold kernel

作者：Wang, Pu; Sun, Xiangxiang; Liu, Xia; Xiong, Lin; Ma, Zhongyun; Wang, Yong; Pei, Yong^*

来源：Nanoscale, 2018, 10(22): 10357-10364.

DOI：10.1039/c8nr00995c

• THIOLATE-PROTECTED AU-38
• CRYSTAL-STRUCTURE
• THEORETICAL-ANALYSIS
• ELECTRONIC-STRUCTURE
• METAL NANOCLUSTERS
• ATOMIC-STRUCTURE
• CLUSTERS
• NANOMOLECULES
• EVOLUTION
• NANOPARTICLE

Coinage metal clusters stabilized by organic ligands such as phosphine or organothiolate are well known to possess multi-twinned gold cores, and the face-centered-cubic (fcc) metal atom packing is unstable until the cluster size reaches a certain threshold. In this study, we searched for the smallest size gold nanocrystal protected by thiolate ligands by means of the crystal facet cleavage (CFC) method. Starting from the nanocrystal-like Au-28(SR)(20) cluster, after cleaving two different crystal facets and patching the ligand shells, we obtained five nanocrystal-like Au-20(SR)(16) isomers. These fcc-structured Au-20 clusters were quite different from non-fcc Au-20(SPh-tBu)(16); the latter's total structure was determined by single X-ray diffraction. By employing dispersion correction density functional theory (DFT-D) calculations and considering ligand effects, we found that fcc-structured Au-20(SR)(16) isomers had comparable or even lower energies when compared with the non-fcc structure found in Au-20(SPh-tBu)(16). Furthermore, the calculation of optical absorption spectra based on predicted fcc isomers indicated that the cubic nanocrystal-like isomer structure is a good candidate to understand the structure of the Au-20(SCH2CH2Ph)(16) cluster.

• 出版日期2018-6-14
• 单位苏州大学; 湘潭大学