Self-Assembly of Catalytically Active Supramolecular Coordination Compounds within Metal–Organic Frameworks

Supramolecular
coordination compounds (SCCs) represent the power
of coordination chemistry methodologies to self-assemble discrete
architectures with targeted properties. SCCs are generally synthesized
in solution, with isolated fully coordinated metal atoms as structural
nodes, thus severely limited as metal-based catalysts. Metal–organic
frameworks (MOFs) show unique features to act as chemical nanoreactors
for the in situ synthesis and stabilization of otherwise
not accessible functional species. Here, we present the self-assembly
of PdII SCCs within the confined space of a pre-formed
MOF (SCCs@MOF) and its post-assembly metalation to give a PdII–AuIII supramolecular assembly, crystallography
underpinned. These SCCs@MOFs catalyze the coupling of boronic acids
and/or alkynes, representative multi-site metal-catalyzed reactions
in which traditional SCCs tend to decompose, and retain their structural
integrity as a consequence of the synergetic hybridization between
SCCs and MOFs. These results open new avenues in both the synthesis
of novel SCCs and their use in heterogeneous metal-based supramolecular
catalysis.

超分子配位化合物（Supramolecular coordination compounds，SCCs）彰显了配位化学方法学通过自组装构建具有目标特性离散结构的强大能力。超分子配位化合物通常在溶液中合成，以孤立的完全配位金属原子作为结构节点，因此作为金属基催化剂时其应用受到极大限制。金属有机框架（Metal–organic frameworks，MOFs）展现出独特的性能，可作为化学纳米反应器，用于原位合成并稳定那些原本难以获取的功能物种。本研究报道了在预合成金属有机框架的受限空间内二价钯基超分子配位化合物的自组装过程（产物记为SCCs@MOF），并通过后组装金属化得到二价钯-三价金超分子组装体，相关结果得到晶体学表征的支撑。这类SCCs@MOF可催化硼酸与炔烃的偶联反应，该反应是一类典型的多位点金属催化反应，传统超分子配位化合物在此类反应中易发生分解，而本体系中的组装体则能保持结构完整性，这得益于超分子配位化合物与金属有机框架之间的协同杂化效应。该研究成果为新型超分子配位化合物的合成，以及其在多相金属基超分子催化领域的应用开辟了全新路径。