Metal–Organic Frameworks Formed from Self-Assembled Polynuclear Silver Halide Clusters

Low-valent metal–organic frameworks (LVMOFs) are an emerging subclass of materials that utilize low oxidation state metal ions for their secondary building units (SBUs). Herein, four LVMOFs and one coordination polymer have been synthesized by combining polytopic phosphine ligands with AgI. In previous examples of LVMOFs, the SBUs are mononuclear metal centers or, in rarer cases, derived from preformed metal clusters. The LVMOFs described here were synthesized from AgI and phosphine ligands resulting in formation of Ag 4 I 4 or Ag 2 I 2 SBUs. These LVMOFs display one-, two-, or three-dimensional structures and are among the only examples of LVMOFs with polynuclear metal-cluster SBUs that form during LVMOF synthesis. In this regard, these LVMOFs form polynuclear SBUs in the same manner as found in more conventional MOFs. Importantly, one LVMOF formed a rare, 3-dimensional, 4-connected topology with only one prior occurrence among MOFs, demonstrating that LVMOFs can generate distinct opportunities in MOF chemistry.