In recent years, Frustrated Lewis Pairs (FLPs) have been widely used in homogeneous catalytic reactions due to their excellent catalytic performance. In classical FLPs, the active centers formed by Lewis acids (LAs) and Lewis bases (LBs) effectively activate small molecules. Furthermore, FLPs are now extensively used in various heterogeneous catalysts, such as zeolites, metal oxide surfaces, and metal/covalent organic frameworks. FLPs-functionalized heterogeneous catalysts exhibit superior catalytic activity and stability in activating small molecules. Recently, the team of Researcher Shen Hui from the Institute of Energy Materials Chemistry at our university collaborated with Academician Zheng Nanfeng from Xiamen University and Professor Li Fengyu from the School of Physical Science and Technology at our university to innovatively embed FLP units on the surface of ligand-stable copper nanoclusters, proposing for the first time the new concept of "hindered Lewis acid-base pairs clusters" (FLPCluster for short). The relevant research results were published in the top international chemistry journal J. Am. Chem. Soc. The title of the paper is "Anchoring Frustrated Lewis Pair Active Sites on Copper Nanoclusters for Regioselective Hydrogenation," and Inner Mongolia University is the first unit listed for this paper.
In this study, the team cleverly modified the surface of copper nanoclusters with thiol ligands containing 2-methoxy groups. In this cluster, thiol ligands are used together with other organic ligands to stabilize the metal core, and what is extremely unique is that the surface methoxy group (LB) of the cluster coordinates with the surface copper atom (LA) to form FLP. Theoretical calculations indicate that it is the FLP active sites on the surface of nanoclusters that activate H2 through heterolytic pathways, thereby achieving efficient catalytic hydrogenation under mild conditions (see figure). In this work, the author used [Cu34S7 (RS) 18 (PPh3) 4] 2+nanoclusters as model catalysts (hereinafter referred to as Cu34, RSH=2-methoxyphenylthiol) to preliminarily explore the practical application of FLPCluster in small molecule activation.
This work creatively introduced FLPs elements onto the surface of atomically precise nanoclusters, resulting in the birth of the first hindered Lewis acid-base pair cluster (FLPCluster) and discovering its excellent catalytic performance. This work demonstrates a new approach combining nanocluster catalysis with FLP catalysis. FLPCluster combines the advantages of hindered Lewis acid-base pairs and nanoclusters. It not only enables small molecule activation like conventional FLPs catalysts, but also provides the possibility for precise regulation of nanocatalysts due to the precise ligand chemistry at the cluster interface.
This work has received strong support from the National Key Research and Development Program, the National Natural Science Foundation, the Steed Plan of Inner Mongolia University, and the Inner Mongolia Youth Science and Technology Talent Development Project.
[Article link]
https://pubs.acs.org/doi/10.1021/jacs.4c10251
