CAU-3: a new family of porous MOFs with a novel Al-based brick: [Al2(OCH3)4(O2C-X-CO2)] (X = aryl).

A new family of Al-based MOFs denoted as CAU-3 (CAU = Christian-Albrechts-Universität) was discovered in the solvothermal system Al(3+)/aryldicarboxylic acid/NaOH/methanol by applying high-throughput-methods. The three compounds reported in this article [Al(2)(OCH(3))(4)BDC], [Al(2)(OCH(3))(4)BDC-NH(2)] and[Al(2)(OCH(3))(4)NDC] (BDC = 1,4-benzenedicarboxylate; NDC = 2,6-naphtalenedicarboxylate) are all based on the same unprecedented inorganic building unit [Al(12)(OCH(3))(24)](12+), which is a dodecameric cyclic aluminium-methanolate-cluster. The material CAU-3-NDC was found to exhibit the highest surface area as well as the highest micropore volume of all Al-based MOFs reported until now.

New functionalized flexible Al-MIL-53-X (X = -Cl, -Br, -CH3, -NO2, -(OH)2) solids: syntheses, characterization, sorption, and breathing behavior.

Five new flexible functionalized aluminum hydroxo terephthalates [Al(OH)(BDC-X)]·n(guests) (BDC = 1,4-benzene-dicarboxylate; X = -Cl, 1-Cl; -Br, 2-Br; -CH(3), 3-CH(3); -NO(2), 4-NO(2); -(OH)(2), 5-OH(2)) were synthesized under solvothermal conditions. The as synthesized (Al-MIL-53-X-AS) as well as the activated compounds were characterized by X-ray powder diffraction (XRPD), IR spectroscopy, thermogravimetric (TG), and elemental analysis. Activation, that is, removal of unreacted H(2)BDC-X molecules and/or occluded solvent molecules, followed by hydration in air at room temperature, led to the narrow pore (NP) form of the title compounds [Al(OH)(BDC-X)]·n(H(2)O) (Al-MIL-53-X). Thermogravimetric analysis (TGA) and temperature-dependent XRPD (TDXRPD) experiments performed on the NP-form of the compounds indicate high thermal stability in the range 325-500 °C. As verified by N(2), CO(2), or H(2)O sorption measurements, most of the thermally activated compounds exhibit significant microporosity. Similar to pristine Al-MIL-53, the present compounds retain their structural flexibility depending on the nature of guest molecules and temperature, as verified by cell parameter determination from XRPD data. The breathing behavior of the functionalized frameworks upon dehydration-rehydration, investigated by temperature and time-dependent XRPD measurements, differs significantly compared to parent Al-MIL-53.

High-throughput and time-resolved energy-dispersive X-ray diffraction (EDXRD) study of the formation of CAU-1-(OH)2: microwave and conventional heating.

Aluminium dihydroxyterephthalate [Al(8)(OH)(4)(OCH(3))(8)(BDC(OH)(2))(6)]⋅x H(2)O (denoted CAU-1-(OH)(2)) was synthesized under solvothermal conditions and characterized by X-ray powder diffraction, IR spectroscopy, sorption measurements, as well as thermogravimetric and elemental analysis. CAU-1-(OH)(2) is isoreticular to CAU-1 and its pores are lined with OH groups. It is stable under ambient conditions and in water, and it exhibits permanent porosity and two types of cavities with effective diameters of approximately 1 and 0.45 nm. The crystallization of CAU-1-(OH)(2) was studied by in situ energy-dispersive X-ray diffraction (EDXRD) experiments in the 120-145 °C temperature range. Two heating methods-conventional and microwave-were investigated. The latter leads to shorter induction periods as well as shorter reaction times. Whereas CAU-1-(OH)(2) is formed at all investigated temperatures using conventional heating, it is only observed below 130 °C using microwave heating. The calculation of the activation energy of the crystallization of CAU-1-(OH)(2) exhibits similar values for microwave and conventional synthesis.

3-D coordination polymers based on the tetrathiafulvalenetetracarboxylate (TTF-TC) derivative: synthesis, characterization, and oxidation issues.

The reactivity of the redox-active tetracarboxylic acid derived from the tetrathiafulvalene (TTF-TC)H(4) with alkaline cations (K, Rb, Cs) is reported. The exploration of various experimental parameters (temperature, pH) led to the formation of four crystalline three-dimensional coordination polymers formulated M(2)(TTF-TC)H(2) (M = K, Rb, Cs), denoted MIL-132(K), MIL-133(isostructural K, Rb), and MIL-134(Cs). Thermogravimetric analysis and thermodiffraction show that all of the solids are thermally stable up to 150-200 degrees C in the air. In order to exploit the possibility of oxidation of the organic linker in TTF-based compounds, they were employed as positive electrodes in a classical lithium cell. A highly reversible cyclability was achieved at high current density (10 C) with a reasonable performance (approximately 50 mAh g(-1)). Finally, combined electro-(sub)hydrothermal synthesis was used to prepare a fifth 3-D coordination polymer formulated K(TTF-TC)H(2) (denoted MIL-135(K)), this time not based on the neutral TTF-TC linker but its radical, oxidized form TTF-TC(+*). This solid is less thermally stable than its neutral counterparts but exhibits a semiconducting behavior, with a conductivity at room temperature of about 1 mS cm(-1).

Oriented growth of the functionalized metal-organic framework CAU-1 on -OH- and -COOH-terminated self-assembled monolayers.

The oriented growth of the amino-functionalized metal-organic framework [Al4(OH)2(OCH3)4(H2N-bdc)3].xH2O (named CAU-1; CAU = Christian-Albrechts-University) on different self-assembled monolayers (SAMs) is reported. Gold substrates were modified with both 16-mercaptohexadecanol and 16-mercaptohexadecanoic acid SAMs and immersed in a pre-treated crystallization solution. The different terminal functionalities and synthesis parameters result in the direct surface growth of CAU-1 crystals along preferred crystallographic orientations. While for the OH-terminated SAMs a preferential attachment of the CAU-1 crystals either in [011] or [002] direction is observed (depending on the reaction conditions), highly oriented crystal growth in [002] orientation was obtained on the carboxylic acid functionalized SAMs.

[Al4(OH)2(OCH3)4(H2N-bdc)3] x xH(2)O: a 12-connected porous metal-organic framework with an unprecedented aluminum-containing brick.

Al together now! A new stable aluminum aminoterephthalate system contains octameric building blocks that are connected by organic linkers to form a 12-connected net (see picture). The structure adopts a cubic centered packing motive in which octameric units replace individual atoms, thus forming distorted octahedral (red sphere) and tetrahedral cages (green spheres) with effective accessible diameters of 1 and 0.45 nm, respectively.

Synthesis and modification of a functionalized 3D open-framework structure with MIL-53 topology.

Aluminum aminoterephthalate Al(OH)[H(2)N-BDC] x 0.3 (H(2)N-H(2)BDC (denoted MIL-53-NH(2)(as)) was synthesized under hydrothermal conditions. The activation of the compound can be achieved in two steps. The treatment with DMF at 150 degrees C leads to Al(OH)[H(2)N-BDC] x 0.95 DMF (MIL-53-NH(2)(DMF)). In the second step, DMF is thermally removed at 130 degrees C. Upon cooling in air, the hydrated form Al(OH)[H(2)N-BDC] x 0.9 H(2)O (MIL-53-NH(2)(lt)) is obtained. The dehydration leads to a porous compound that exhibits hysteresis behavior in the N(2) sorption experiments. The MIL-53-NH(2)(lt) can be modified by postsynthetic functionalization using formic acid, and the corresponding amide Al(OH)[HC(O)N(H)-BDC] x H(2)O (MIL-53-NHCHO) is formed. All four phases were thoroughly characterized by X-ray powder diffraction, solid-state NMR and IR spectroscopy, and sorption measurements, as well as thermogravimetric and elemental analysis. Based on the refined lattice parameter similar breathing behavior of the framework as found in the unfunctionalized MIL-53 can be deduced. Solid-state NMR spectra unequivocally demonstrate the presence of the guest species, as well as the successful postsynthetic functionalization.