Based on the V-shaped linker molecule 4,4'-benzophenonedicarboxylic acid, the new carbonyl-functionalized metal-organic framework (MOF) [Al(OH)(O(2)C-C(6)H(4)-CO-C(6)H(4)-CO(2))], denoted as CAU-8, was discovered employing high-throughput methods. The compound is obtained from 4,4'-benzophenonedicarboxylic acid, Al(2)(SO(4))(3)·18H(2)O in a mixture of N,N-dimethylformamide (DMF) and water under solvothermal conditions. The structure was determined from single-crystal X-ray diffraction data (I4(1)/a, a = b = 13.0625(5), c = 52.565(2) Å). The framework is based on infinite inorganic building units of trans-connected, corner-sharing AlO(6)-polyhedra. Parallel Al-O-chains are arranged in layers perpendicular to [001]. Within a layer an interchain distance of ∼1.1 nm is observed. The orientation of the Al-O-chains within neighboring layers is perpendicular to each other, along [100] and [010], respectively, and an ABCDA stacking of these layers is observed. The interconnection of these orthogonally oriented chains by the V-shaped dicarboxylate ions results in the formation a three-dimensional framework structure containing one-dimensional channels with a diameter of about 8 Å. The pore walls are lined by the keto-groups. CAU-8 was thoroughly characterized by X-ray powder diffraction (XRPD), thermogravimetric measurements, IR- and Raman-spectroscopy, elemental analysis, and gas sorption experiments using N(2) and H(2) as adsorptives. CAU-8 is stable up to 350 °C in air and exhibits a moderate porosity with a specific surface area of S(BET) = 600 m(2)/g and a micropore volume of 0.23 cm(3)/g. Moreover, a detailed topological analysis of the framework was carried out, and an approach for the topological analysis of MOFs based on infinite 1-periodic building units is proposed.

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Graphenes as metal-free catalysts for the oxidative depolymerization of lignin modelsJuan F. Blandez, [b] Sergio Navalón, [b] Mercedes Alvaro, [b] and Hermenegildo Garcia* [a] Abstract: Graphene oxide promotes the oxidative degradation of guaiacylglycerol-β-guaiacyl ether, a lignin model compound, in different solvents including acetonitrile, toluene and water mainly to guaiacol, 2-methoxyquinone, vanillic acid and coniferyl aldehyde.Reduced graphene oxide and B-doped graphene exhibit similar activity as graphene oxide. Control experiments indicate that metal impurities should play a marginal role in the observed catalytic activity.

The in situ and systematic high-throughput investigation of the system Al/4,4'-benzophenonedicarboxylic acid (HBPDC)/DMF/HO in the presence of various additives was carried out, and a new Al-MOF of composition [Al(OH)(BPDC)], denoted as CAU-21-BPDC, was obtained. Its crystal structure was determined from single-crystal X-ray diffraction data (space group I422, a = b = 17.2528(7) Å, c = 23.864(1) Å). The structure is built up by octanuclear rings of cis corner-sharing AlO polyhedra forming the inorganic building unit (IBU). These {AlO} IBUs are arranged in a bcu packing and connected via BPDC ions in a way that each IBU is linked via two linker molecules to each of the eight adjacent IBUs. Thus, accessible, one-dimensional modulated pores with a diameter between 3.6 and 6.5 Å are formed. In addition, tetrahedral cavities are formed by the BPDC linker molecules. The framework of CAU-21-BPDC is polymorphous with that of CAU-8-BPDC, which contains one-dimensional chains of trans corner-sharing AlO polyhedra connected by BPDC ions. Replacing HBPDC by 4,4'-oxydibenzoic acid (HODB), which contains an oxygen atom between the phenyl rings instead of a keto group, leads to the synthesis of Al-MOFs isoreticular with CAU-8-BPDC and CAU-21-BPDC. In addition, a coordination polymer, [Al(HODB)(OH)], was discovered and structurally characterized. The structure of CAU-8-ODB was refined from powder X-ray diffraction data, while a Pawley refinement was carried out for CAU-21-ODB to determine the lattice parameters and confirm phase purity. The structure of CAU-21-ODB was confirmed using density functional theory (DFT) calculations. A thorough characterization shows that the CAU-8 and CAU-21-type structures are stable up to 350 and 300 °C in air, respectively, almost independent of the linker molecules incorporated. The former MOFs are porous toward N and CO, while the latter only adsorb CO.