“Fluoride molecular scissors”: A rational construction of new Mo(VI) oxofluorido/1,2,4-triazole MOFs

New molybdenum(VI) oxofluoride-organic hybrids, [Mo2F2O5(tr2ad)] (1) and [Mo2F2O5(tr2ad2)] (2), supported by angular or linear N1,N2-(1,2,4-triazol-4-yl) bridges (tr2ad, 1,3-bis(1,2,4-triazol-4-yl)adamantane; tr2ad2, 3,3′-bis(1,2,4-triazol-4-yl)-1,1′-biadamantane), were prepared in an aqueous HF solution under hydrothermal conditions. The structure of the compounds includes dinuclear corner-sharing {Mo2F2O5} cores, in which two octahedral Mo ions are linked by one oxygen atom (Mo-O 1.90–1.92 Å) and two triazolyl groups (Mo-N 2.37–2.40 Å). The latter occupy the cis-positions in the {Mo2F2O5(tr)2} coordination clusters (“secondary building blocks”). Terminal fluoride and two “molybdenyl” oxygen atoms complete the coordination sphere of each molybdenum ions. In both cases the ligands show the maximal tetradentate mode connecting the adjacent inorganic units into a zigzag chain.

The fluoride ions, as terminal ligands, were employed for the modification of inorganic subtopology of the metal oxide-organic frameworks (MOOFs).Figure optionsDownload as PowerPoint slideResearch highlights
► Fluoride ligands terminate inorganic subconnectivity of metal oxide-organic frameworks.
► 1,2,4-triazoles are efficient ligands for bridging Mo(VI) ions.
► Adamantane is a suitable molecular platform for design of bitriazole tectons.