Synthesis and Porous Properties of Chromium Azolate Porous Coordination Polymers

We developed a new
route for synthesis of Cr-based porous coordination polymers (PCPs)
with azole ligands and characterized the unique open structures by
single-crystal X-ray studies and other spectroscopy techniques. Chromium-based
PCPs have been prepared from azolate ligands 3,5-dimethyl-1H-pyrazole-4-carboxylic acid (H2dmcpz) and 1,4-di­(1H-tetrazole-5yl)­benzene (H2BDT) by solvothermal
reactions under an Ar atmosphere. [Cr3O­(Hdmcpz)6(DMF)3]⊃DMF (1⊃DMF) is a coordination
compound that forms a hydrogen-bonded porous network. [Cr3O­(HBDT)2(BDT)­Cl3)]⊃DMF (2⊃DMF) possesses a new type of trinuclear chromium μ3-O unit cluster and the novel topology of a Cr-based PCP with
700 m2 g–1 of Brunauer–Emmett–Teller
surface area. [Cr­(BDT)­(DEF)]⊃DEF (3⊃DEF)
is structurally flexible and reactive to O2 molecules because
of the unsaturated Cr2+ centers. This is the first report
of a Cr-based PCP/metal–organic framework with noncarboxylate
ligands and characterization by single-crystal X-ray diffraction.