A new aluminium-based microporous metal–organic framework: Al(BTB) (BTB = 1,3,5-benzenetrisbenzoate)

The system Al3+/H3BTB/DMF/additive was systematically investigated using high-throughput methods and the new, microporous MOF [Al(BTB)] (BTB = 1,3,5-benzenetrisbenzoate), named CAU-4 (CAU = Christian-Albrechts-University), was discovered. The synthesis was optimized changing chemical and process parameters and the final synthesis procedure was scaled up to the gram scale. CAU-4 is thermally stable up to 400 °C in air and exhibits a BET-surface area of 1520 m2/g and a micropore volume of 0.61 cm3/g. A structure model was developed using a computationally assisted structure determination that was further validated by a good agreement with the experimental X-ray diffraction patterns and the geometrical features. The framework structure consists of isolated [AlO6]-octahedra which are bridged by carboxylate groups of the BTB-linker to form chains. These chains are connected by the tritopic aromatic building blocks, to form one-dimensional hexagonal channels with a diameter of ca. 9.6 Å.

Figure optionsDownload as PowerPoint slideHighlights
► CAU4 is a new, highly porous and thermally stable Al-containing MOF.
► CAU-4 contains one-dimensional pores with a diameter of ∼1 nm.
► Structure simulation and spectroscopic investigations led to a structural model.