Multimetallic cluster complexes as well-defined nano-scale catalysts for novel organic transformations

多金属簇合物由于其近端金属中心可作为独特的有机转化的反应中心而被广泛研究。我们以前报道过一个四核锌原子簇在有胺官能团存在的情况下催化选择性酯交换反应，其选择性与无簇催化剂的反应条件相反。基于四核锌簇合物独特的反应性，我们应用了几种多金属簇合物作为酯转化催化剂。在我们的研究中，我们发现多金属原子簇和氮基配体的混合物导致了配体与簇基序配位后形成高活性物种。在锌原子簇催化的几种酯转化反应中也观察到了这种增强效应，此外，加入2，2‘-联吡啶后，八核钴原子簇成为酯交换反应的优良催化剂。因此，在催化反应中通过使用额外的配体进行这种簇合物转化是展示高催化性能的一般策略。

Multimetallic cluster complexes have been extensively studied due to their applicability of proximal metal centers as a reactive site for unique organic transformations. We previously reported a tetranuclear zinc cluster catalyzed selective trans-esterification in the presence of amine functionalities, and the selectivity was opposite trend to the cluster catalyst free reaction condition. Based on the unique reactivity of the tetranuclear zinc cluster, we applied several multimetallic cluster complexes as catalysts for ester transformations. During our research, we found that the mixture of multimetallic clusters and nitrogen-based ligands led to the formation of highly reactive species after the coordination of the ligands to the cluster motif. Such enhancement effects were observed in zinc cluster catalyzed several ester transformations, and in addition, octanuclear cobalt clusters became an excellent catalyst for trans-esterification upon addition of 2,2’-bipyridine. Therefore, such cluster transformation during the catalytic reaction by using additional ligands is general strategy for showing high catalytic performance.