During my stay in Kaust, I directed my master student Emilie on an interesting project, looking for novel highly connected nets. Unfortunately master internships don’t last forever and the project stayed in standby until my friend Zhijie Chen gave it a second breath. An amazing one. I am really impressed by the achievements here.
This is structure design, period.
Our article has just been accepted in the Journal of the American Chemical Society.
Abstract: Highly-connected and edge-transitive nets are of prime importance in crystal chemistry, and regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). We report the design and synthesis of highly-connected MOFs based on reticulation of the sole two edge-transitive nets with a vertex-figure as double six-membered ring (d6R) building-unit, namely (4,12)-coordinated shp net (square and hexagonal-prism) and (6,12)-coordinated alb net (aluminium diboride, hexagonal-prism and trigonal-prism). Decidedly, the combination of our recently isolated 12-connected rare-earth (RE) nonanuclear [RE9(μ3-OH)12(μ3-O)2(O2C−)12] carboxylate-based cluster, points of extension matching the 12 vertices of hexagonal-prism (d6R), with 4-connected square porphyrinic tetra-carboxylate ligand led to the formation of the targeted RE-shp-MOF. This is the first time that RE-MOFs based on 12-connected molecular building blocks (MBBs), d6R building-units, are deliberately targeted and successfully isolated, paving the way for the long-awaited (6,12)-c MOF with alb topology. Certainly, a custom-designed hexa-carboxylate ligand and its combination with RE salts led to the formation of the first related alb-MOF, RE-alb-MOF. Intuitively, we successfully transplanted the alb topology to another chemical system and constructed the first indium-based alb-MOF, In-alb-MOF, by employing trinuclear [In3(μ3-O)(O2C−)6] as the requisite 6-connected trigonal-prism and purposely-made dodecacarboxylate ligand as a compatible 12-c MBB. Prominently, the dodecacarboxylate ligand was employed to transplant shp topology into copper-based MOFs by employing copper-paddlewheel [Cu2(O2C−)4] as the complementary square building-unit and affording the first Cu-shp-MOF. We revealed that highly-connected edge-transitive nets such shp and alb are ideal for topological transplantation and deliberate construction of related MOFs based on minimal edge-transitive nets.