Os(VI)O₂/K Metal–Organic Frameworks: Infinite Chain, Grid, and Porous Networks

The design of multianionic chelating ligands as new organic linker for producing metal–organic frameworks (MOFs) is discussed. Three potentially polyanionic pro-ligands, 3,5-di-tert-butyl-2-hydroxy-N-(2-hydroxyethyl)­benzamide (1LH3), bis­(2-aminoethyl)-5-(tert-butyl)-2-hydroxyisophthalate (2aLH3), and 5-(tert-butyl)-2-hydroxy-N1,N3-bis­(1-hydroxy-2-methylpropan-2-yl)­isophthalamide (2bLH3), were synthesized and found to coordinate the osmyl ion in trianionic NO2 fashion through the N-amidate, O-phenolate, and O-alcoholate donor atoms. The X-ray crystal structures of three dioxo-Os­(VI) complexes: [Os2O4(1L)2(OH)­K2(H2O)­(C3H6O)] (Os1), [OsO2(2aL3–)­(MeOH)4(MeO)­K2] (Os2a), and [OsO2(2bL)­(H2O)­(C3H6O)­K] (Os2b) reveal that the osmyl moiety and the ligand establish distinctive interactions with the potassium ions, yielding unprecedented infinite network from stepladder chain (in Os2b) and 2D-grid (in Os1) to 3D-porous H-bonding network (in Os2a).