Free-standing, accessible thiol (-SH) functions have been installed in robust, porous coordination networks to provide wide-ranging reactivities and properties in the solid state. The frameworks were assembled by reacting ZrCl4 or AlCl3 with 2,5-dimercapto-1,4-benzenedicarboxylic acid (H2DMBD), which features the hard carboxyl and soft thiol functions. The resultant Zr-DMBD and Al-DMBD frameworks exhibit the UiO-66 and CAU-1 topologies, respectively, with the carboxyl bonded to the hard Zr(IV) or Al(III) center and the thiol groups decorating the pores. The thiol-laced Zr-DMBD crystals lower the Hg(II) concentration in water below 0.01 ppm and effectively take up Hg from the vapor phase. The Zr-DMBD solid also features a nearly white photoluminescence that is distinctly quenched after Hg uptake. The carboxyl/thiol combination thus illustrates the wider applicability of the hard-and-soft strategy for functional frameworks.

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We report the first zirconium metal-organic framework based on squaric acid, representing the member with the smallest unit cell in the isoreticular UiO-66 family. Its molecular sieving properties are strongly influenced by the monocarboxylic acid modulator incorporated during synthesis.

The resistance of metal-organic frameworks towards water is a very critical issue concerning their practical use. Recently, it was shown for microporous MOFs that the water stability could be increased by introducing hydrophobic pendant groups. Here, we demonstrate a remarkable stabilisation of the mesoporous MOF Al-MIL-101-NH2 by postsynthetic modification with phenyl isocyanate. In this process 86 % of the amino groups were converted into phenylurea units. As a consequence, the long-term stability of Al-MIL-101-URPh in liquid water could be extended beyond a week. In water saturated atmospheres Al-MIL-101-URPh decomposed at least 12-times slower than the unfunctionalised analogue. To study the underlying processes both materials were characterised by Ar, N2 and H2 O sorption measurements, powder X-ray diffraction, thermogravimetric and chemical analysis as well as solid-state NMR and IR spectroscopy. Postsynthetic modification decreased the BET equivalent surface area from 3363 to 1555 m(2)  g(-1) for Al-MIL-101-URPh and reduced the mean diameters of the mesopores by 0.6 nm without degrading the structure significantly and reducing thermal stability. In spite of similar water uptake capacities, the relative humidity-dependent uptake of Al-MIL-101-URPh is slowed and occurs at higher relative humidity values. In combination with (1) H-(27) Al D-HMQC NMR spectroscopy experiments this favours a shielding mechanism of the Al clusters by the pendant phenyl groups and rules out pore blocking.

Ten mixed-linker metal-organic frameworks [Al(OH)(m-BDC-X)(1-y)(m-BDC-SO3H)y] (H2BDC = 1,3-benzenedicarboxylic acid; X = H, NO2, OH) exhibiting the CAU-10-type structure were synthesized. The compounds can be grouped into three series according to the combination of ligands employed. The three series of compounds were obtained by employing different ratios of m-H2 BDC-X and m-H2BDC-SO3Li. The resulting compounds, which are denoted CAU-10-H/Sx, -N/Sx and -O/Sx, show exceptionally high thermal stability for sulfonated materials of up to 350 °C. Detailed characterization with special focus on polarity and acidity was performed, and the impact of the additional SO3H groups is clearly demonstrated by changes in the sorption affinities/capacities towards several gases and water vapor. In addition, selected samples were evaluated for proton conductivity and as catalysts for the gas-phase dehydration of ethanol to ethylene. While only very low proton conductivities were observed, a pronounced increase in catalytic activity was achieved. Although reactions were performed at temperatures of 250 and 300 °C for more than 40 h, no desulfonation and no loss of crystallinity were observed, and stable ethanol conversion resulted. This demonstrates the high stability of this material.

One-dimensional crystalline heterostructures of two types of nanoreactors strictly alternating along the stacking direction are obtained by partial ion exchange into a synthetic clay mineral distinguished by an outstandingly homogeneous charge density. The driving force for the formation of these high interface architectures is proven to be founded in densely packed cationic molecules in the interlayer with a charge density deviating from the charge density of the host clay mineral. The established mechanism renders the approach generally applicable and will allow for synthesis of ordered heterostructures of any desired combination of functional molecules that moreover are separated by exactly 1 nm thick silicate walls. The ordered heterostructures were furthermore shown to represent the thermodynamic equilibrium suggesting the mechanism of formation to be robust.

Abstract.A new rigid metal-organic framework (MOF) with MIL-53 topology built of 2,5-thiophenedicarboxylate (TDC) and Al, Ga, or In is reported. Its structure contains chains of trans corner sharing MO 6 octahedra, connected by the linker molecules to form microporous square shaped 1D channels. A combination of powder X-ray diffraction (PXRD), density functional theory (DFT) calculations, and 1 H, 13 C, and 27 Al solid-state NMR spectroscopy (ssNMR) was used to analyse the structures in detail. The synthesis is easily scaled-up using microwave assisted solvothermal conditions. All materials possess a

A new sulfone-functionalized metal-organic framework [Al(OH)(SDBA)]·0.25DMF, denoted CAU-11, was synthesized using a V-shaped linker molecule 4,4'-sulfonyldibenzoic acid (H2SDBA). The crystal structure was solved from synchrotron X-ray powder diffraction data. Chains of trans corner-sharing AlO6 octahedra are interconnected by the carboxylate groups to form layers (ABAB stacking). Within the layers, hydrophobic lozenge-shaped pores with a diameter of 6.4 × 7.1 Å(2) are present inducing permanent porosity (aBET = 350 m(2) g(-1) and Vmicro = 0.17 cm(3) g(-1)). With the application of HT-methods (HT = high throughput), the isoreticular carboxylate functionalized compound [Al(OH)(H2DPSTC)]·0.5H2O (CAU-11-COOH) was synthesized using the linker molecule 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DPSDA), which hydrolyzes under the reaction conditions. Due to the additional noncoordinating carboxylic acid groups the pores are hydrophilic. Changing the molar ratio of Al(3+) to linker lead to the discovery of a second new compound [Al2(OH)2(DPSTC)(H2O)2]·0.5H2O (CAU-12). In CAU-12 the linker molecule is fully deprotonated which leads to different connectivity compared to the structure of CAU-11-COOH. Thermal activation of CAU-12 leads to dehydration and transformation of the structure to [Al2(OH)2(DPSTC)]·nH2O (CAU-12-dehy). Coordinated water molecules were removed, and the coordination site is replaced by the previously noncoordinating O atom of the adjacent carboxylate group. The SO2-groups point into the pores resulting in a highly hydrophobic three-dimensional framework. The compounds exhibit high thermal stability in air at least up to 420 °C. Synthesis of CAU-11 can be easily scaled up in very high yields (98%).