A calixarene-based metal-organic framework (Zr-cal, [Zr O (OH) (FA) ] (cal) ], FA=formate, cal=1,3-alt-25,26,27,28-tetrakis[(carboxy)methoxy]calixarene) was synthesized and characterized by single-crystal X-ray diffraction. The three-dimensional framework is a 4,6-connected network of gar topology and exhibits two equal but nonintersecting three-dimensional pore systems. It has a specific BET surface area of 670 m g , and the calixarene cavities are accessible through the pore systems. The exposed calixarenes can be used for the visual detection and encapsulation of NO through the formation of deeply colored charge-transfer complexes inside the MOF. The highly selective complexation was analyzed by UV/Vis and IR spectroscopy, and the stability of the material was confirmed by powder X-ray diffraction and H NMR spectroscopy. Finally, the MOF was used as a sensor material in a home-made sensor cell and showed high sensitivity for NO .

In as ystematic investigation,t he synthesis of metal-organicf rameworks (MOFs) with MIL-140 structure was studied. The precursors of this family of MOFs are the same as for the formation of the well-known UiO-typeM OFs although the synthesis temperature for MIL-140 is significantly higher. This study is focused on the formationo fZ rbased MIL-140M OFs with terephthalic acid (H 2 bdc), biphenyl-4,4'-dicarboxylic acid (H 2 bpdc), and4 ,4'-stilbenedicarboxylic acid (H 2 sdc)a nd the introduction of synthesis field diagrams to discover parameters for phase-pure products. In this context, aM IL-140n etwork with H 2 sdc as linkerm ole-cule is first reported. Additionally,a ni mportanta spect is the reduction of the synthesis temperature to make MIL-140 MOFsm ore accessible even though linkersw ith am ore delicate nature are used.T he solvothermal syntheses were conductedi nh ighly concentratedr eactionm ixtures whereby a targeted synthesis to yield the MIL-140p hase is possible. Furthermore, the effect of the often-used modulator approachi se xamined for these systems. Finally, the characteristics of the synthesized MOFs are compared with physisorption measurements, thermogravimetric analyses, and scanning electron microscopy.

Nanoparticle-based lyogels or aerogels represent a type of bridge between the macroscopic and nanoscopic world, while these structures are used to demonstrate the feasibility of cation exchange reactions on such macroscopic nanomaterials.