Twelve-connected nanographene-based metal-organic frameworks

The dodeca-carboxylate hexakis[3,5-bis( p -carboxyphenyl)-4,6-dimethoxyphenyl]hexabenzocoronene (HBC-LH12) molecule was synthesized, in which twelve carboxylate groups allow it to function as a twelve-connected linker. Reticulation of HBC-LH12 with yttrium(III) and uranium(VI) yielded two three-dimensional metal-organic frameworks (MOFs), termed MOF-1989 and MOF-1990, respectively. In MOF-1989, the linker, which has both hexagonal and triangular shapes with an overall hexagonal prismatic geometry, is joined by yttrium secondary building units (SBUs) of hexagonal prismatic shape to give an unprecedented edge-2-transitive (3,6,12)-c epu net. While in MOF-1990, this same linker is coordinated to triangular-shaped uranium nodes, generating triangular-triangular-hexagonal sequences and resulting in a (3,3,6)-c mzr net. The development and use of this molecule as a linker has led to new MOFs representing topologies and SBUs heretofore unobserved in reticular chemistry.