PUB - Publikationen an der Universität Bielefeld

Metal-organic frameworks (MOFs) form the class of porous materials with the highest surface areas. This characteristic property combined with the variability of both building blocks, the inorganic node and the organic linker, makes many scientists dream of materials with very special chemical, electronic, optic and/or magnetic properties. For individual applications both building blocks, but also possibly in the framework embedded guests, play a crucial role. This work describes the synthesis of linear, shape-accurate dicarboxylic acids with a length between 1.4 and 3.9 nm consisting of conjugated phenylene and/or ethynylene units for the assembly of MOFs. The dicarboxylic acids bear simple side chains of different length and polarity or chemical addressable, functional groups. The side chains have a direct influence on the chemical interior of the cavities within the MOFs and in the case of accessible functional groups can be chemically transformed. For the exploration of the postsynthetic possibilities Zr-MOFs are especially eligible due to their exceptional high chemical stability. In this work amongst others postsynthetic cycloadditions of propargyl and furan-2-yl groups on interpenetrated Zr-MOFs with very high conversions were performed. For the determination of the conversion via 1H NMR spectroscopy a facile method was developed to dissolve the chemical resistant Zr-MOFs. It includes CsF and DCl in DMSO-d6 and D2O as well as the addition of K2CO3 after dissolving the MOF. Furthermore four polar, silyl-based protecting groups for terminal alkynes were designed. They carry, as a polar tag, a methoxyphenyl group which facilitates chromatographic separations. The steric shielding of the silicon centre differs due to variable alkyl substituents whereby the four polar protecting groups cover the spectrum of the stabilities of the unpolar, silyl-based alkynyl protecting groups and even go beyond it.