Metal–Organic Frameworks Containing (Alkynyl)Gold Functionalities: A Comparative Evaluation of Solvent-Assisted Linker Exchange, <i>de Novo</i> Synthesis, and Post-synthesis Modification

A series of metal–organic framework (MOF) materials containing AuI-carbon covalent bonds was prepared by solvent-assisted linker exchange (SALE) between (alkynyl)­gold­(phosphine)-functionalized bipyridine linkers and the bipyridyl naphthalene tetracarboxydiimide struts in Zn pillared-paddlewheel MOFs. These new materials could not be obtained by the authors through de novo synthesis or post-synthesis modification, both of which lead to the decomposition of the organometallic complex. In contrast, the SALE process occurs readily under mild conditions that preserve the integrity of both the pillared-paddlewheel structure and the organometallic complex. For bipyridine linkers with similar basicities, the rate of the SALE exhibits a strong inverse dependence on the size of the phosphine ligand in the incoming (alkynyl)­gold­(phosphine)-functionalized linker, with smaller ligands reacting faster.本研究通过（炔基金（膦））功能化联吡啶配体与锌柱桨轮型金属有机框架（metal–organic framework, MOF）中的联吡啶基萘四甲酰二亚胺支柱之间的溶剂辅助配体交换（solvent-assisted linker exchange, SALE），制备了一系列含有一价金-碳共价键的金属有机框架（MOF）材料。 作者此前无法通过从头合成或后合成修饰获得该类新型材料——两种方法均会导致该有机金属配合物发生分解。 与之相比，SALE过程可在温和条件下顺利进行，且能够完整保留柱桨轮型框架结构与有机金属配合物的结构完整性。 对于碱性相近的联吡啶配体而言，SALE反应速率与引入的（炔基金（膦））功能化配体中的膦配体尺寸呈显著负相关，即配体尺寸越小，反应速率越快。