Merging and Clipping\nNets for the Synthesis of Three-\nand Two-Merged Net Metal–Organic Frameworks

Herein, we report how merging and clipping nets in metal–organic\nframeworks (MOFs) can be controlled in a single-crystal-to-single-crystal\nfashion using three different approachesthe merged net, clip-off\nchemistry, and linker reinstallationto design and synthesize\nthree- and two-merged net MOFs. Initially, we show the formation of\nthree isoreticular three-merged net MOFs by linking a trimeric Sc<sup>3+</sup> cluster, Sc<sub>3</sub>(μ<sub>3</sub>-Ο)(−COO)<sub>6</sub>, with ditopic zigzag and tritopic linkers. The resulting\nMOFs exhibit three-merged edge-transitive nets<b>kgd</b> + <b>hxl</b> + <b>pcu</b>for the first time.\nThen, using these three-merged net MOFs as precursors, we selectively\nremove one of these subnets, the <b>hxl</b> net, via clip-off\nchemistry to form two-merged net MOFs. This process involves the cleavage\nof olefinic groups via ozonolysis, providing the resulting two-merged\nnet MOFs with free carboxylic acid groups that can be used to tune\ntheir sorption properties such as the removal of cationic organic\npollutants. Finally, we use the linker reinstallation approach to\nconvert the two-merged net MOFs back to the three-merged net MOFs.\nThis approach allows for the postsynthetic addition of the previously\nremoved <b>hxl</b> merged net, enabling recovery of the initial\nthree-merged net MOFs or synthesis of new ones using novel ditopic\nzigzag linkers.