Professor Zheng Nanfeng's research group and collaborators of School of chemistry and chemical engineering of Xiamen University have made important progress in the research of metal clusters

Recently, Professor Zheng Nanfeng, School of chemistry and chemical engineering, Xiamen University, Hannu h ä kkinen, University of Weasley, Finland, and Professor Birger Dittrich, University of Dusseldorf, Germany, have made important progress in the cooperative research on the growth and stability mechanism of metal nanoclusters The relevant research results are as follows: "co crystallization of atomic precise metal Nanoparticals "Driven by magic atomic and electronic shells" was published in nature communications (2018, 9, 3357) It is very important to understand the formation mechanism and stability mechanism of metal nanoclusters for the precise preparation of specific nanostructured metal materials, but the related research is very challenging For a long time, there have been many views on the stability mechanism of metal nanoclusters The main theory to explain the stability of metal nanoclusters is that they have an electron closed shell structure However, there are also a lot of research reports on the stability of metal nanoclusters through the dense packing of atomic geometry in the literature The results show that the two mechanisms of electron shell closure and atom packing play the same important role in the synthesis of metal nanoclusters Two kinds of nanoclusters (AuAg) 267 and (AuAg) 45 were obtained in the same synthesis reaction with mercaptan and organophosphine ligands as protective ligands X-ray single crystal diffraction revealed that the (AuAg) 267 nanoclusters in the eutectic have a nearly perfect spherical structure, with the most dense multi-layer atomic packing structure, i.e Mackay / anti Mackay stacked concentric atomic multi shell structure (1 + 12 + 42 + 92 + 120 atoms), and the outermost layer is stabilized by a highly symmetrical 80 mercaptan ligand The free electron number of (AuAg) 267 nanoclusters is 187, and there is no closed shell structure DFT not only reveals that there is no HOMO-LUMO gap in (AuAg) 267, but also explains the unique UV-Vis absorption spectrum (surface plasmon resonance absorption characteristics) and electrochemical behavior of the metal cluster The smaller (AuAg) 45 clusters in the eutectic are co protected by 27 mercaptans and 6 organophosphine ligands They have a closed shell structure with 18 valence electrons, large HOMO-LUMO energy gap and similar molecular characteristics of UV-Vis absorption spectrum Interestingly, through the two different mechanisms of "magic" atom shell by shell most dense stacking and electron shell closing, the stable size of metal nanoclusters can be assembled to form ordered super structure crystals, in which the weak interaction between the (organic) ligand layers directly affects the super structure There are few reports on the formation of eutectic in different metal nanoclusters This work provides important guidance for understanding the mechanism of stability and assembly behavior of different metal nanoclusters Under the guidance of Professor Zheng Nanfeng, the work was jointly completed by Xiamen University, University of westerly in Finland and University of Dusseldorf in Germany The first author was Yan juanju, a doctoral student jointly trained by academician Zheng Lansun and Professor Zheng Nanfeng The research work was supported by the Ministry of science and technology and the National Natural Science Foundation of China.