The control of structural transformations triggered by external signals is important for the development of novel functional devices. In the present study, it is demonstrated that helicates can be designed to structurally respond to the presence of different counterions and to adopt either a compressed or an expanded structure. Reversible switching is not only possible between those two states, furthermore, the twist of the aggregate also can be controlled. Thus, three out of four possible states of a helicate (expanded/left-handed, expanded/right-handed, compressed/left-handed) based on an enantiomerically pure ester bridged dicatecholate ligand are specifically addressed by introduction, exchange, or removal of countercations. This approach is used to reversibly switch between the different states or to successively address them.

The co-production of formic acid during the conversion of cellulose to levulinic acid offers the possibility for on-site hydrogen production and reductive transformations. Phosphorus-based porous polymers loaded with Ru complexes exhibit high activity and selectivity in the base-free decomposition of formic acid to CO2 and H2 . A polymeric analogue of 1,2-bis(diphenylphosphino)ethane (DPPE) gave the best results in terms of performance and stability. Recycling tests revealed low levels of leaching and only a gradual decrease in the activity over seven runs. An applicability study revealed that these catalysts even facilitate selective removal of formic acid from crude product mixtures arising from the synthesis of levulinic acid.

We offer insights into how network topology influences stability of metal-organic frameworks and suggest the application of rare sheet-MOFs, where metal ions and linkers form infinite 2D units (SBUs) as a strategy for achieving higher stability. We also demonstrate a unified topology approach to MOFs exemplified by the dot-, rod-, and sheet-MOFs reported. These MOFs are based on vicinal dicarboxylates, which we propose as a way to prepare rod-MOFs. Cyclic voltammetry suggests Ce(IV)-MOFs as being more stable than expected with potential electrochemical applications.

The synthesis of a new triaminoguanidinium‐based ligand with three tris‐chelating [NNO]‐binding pockets and C3 symmetry is described. The reaction of tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidinium salts with zinc(II) formate leads to the formation of cyclic supramolecular coordination compounds which in solution bind fullerenes in their spherical cavities. The rapid encapsulation of C60 can be observed by NMR spectroscopy and single‐crystal X‐ray diffraction and is verified using computation.

The reaction of C3‐symmetric tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidinium salts ([H3L]X) and zinc(II) in presence of thiocyanate and different carboxylate ions as co‐ligands yields in a series of different coordination compounds. Supramolecular metallocycles and carboxylate‐bridged dimers are defined by two fundamentally different binding motifs. By adjusting the co‐ligands’ stoichiometry, metallocycles and carboxylate‐bridged compounds can be synthesized selectively. Furthermore, the occupation of the metallocycles with co‐ligands can also be controlled that way. Directed synthesis of these metallocycles is essential for further application in host‐guest chemistry due to their cavities and porosity in the solid state.