Tang Qing, Li Fuhua, Jiang De-En
School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
Department of Chemistry, University of California, Riverside, California 92521, United States.
ACS Nanosci Au. 2021 Oct 26;2(1):40-48. doi: 10.1021/acsnanoscienceau.1c00024. eCollection 2022 Feb 16.
The past decade has witnessed significant advances in the synthesis and structure determination of atomically precise metal nanoclusters. However, little is known about the condensed matter properties of these nanosized metal nanoclusters packed in a crystal lattice under high pressure. Here using density functional theory calculations, we simulate the crystal of a representative superatomic gold cluster, Au(SR) (R = CH), under various pressures. At ambient conditions, Au(SCH) clusters are packed in a crystal via dispersion interactions; being a 7e superatom, each cluster carries a magnetic moment of 1 μ or one unpaired electron. Upon increasing compression (from 10 to 110 GPa), we observe the formation of intercluster Au-Au, Au-S, and S-S covalent bonds between staple motifs, thereby linking the clusters into a network. The pressure-induced structural change is accompanied by the vanishment of the magnetic moment and the semiconductor-to-metal transition. Our work shows that subjecting crystals of atomically precise metal nanoclusters to high pressures could lead to new crystalline states and physical properties.
在过去十年中，原子精确的金属纳米团簇的合成和结构测定取得了重大进展。然而，对于这些在高压下堆积在晶格中的纳米尺寸金属纳米团簇的凝聚态性质却知之甚少。在此，我们使用密度泛函理论计算，模拟了具有代表性的超原子金团簇Au(SR) （R = CH）在各种压力下的晶体结构。在环境条件下，Au(SCH) 团簇通过色散相互作用堆积在晶体中；作为一个7e超原子，每个团簇具有1 μ的磁矩或一个未配对电子。随着压缩程度的增加（从10 GPa到110 GPa），我们观察到在主链基序之间形成了团簇间的Au-Au、Au-S和S-S共价键，从而将团簇连接成一个网络。压力诱导的结构变化伴随着磁矩的消失和半导体到金属的转变。我们的工作表明，对原子精确的金属纳米团簇晶体施加高压可能会导致新的晶体状态和物理性质。
