Interpenetrating coordination cages: Understanding of formation and guest binding, application as multitopic organizational units and aggregation into higher order structures

• Applicant: Professor Dr. Guido Clever
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2012 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 231349046

Metal-mediated self-assembly of supramolecular structures allows for step-wise approaching the structural and functional complexity of biological nano structures. Coordination cages with their inner cavity show potential to study basic features of host-guest phenomena, mechanical transformations and stimuli-responsive behaviour. Possible applications include selective recognition, catalysis, molecular electronics and smart materials. With a focus on palladium-based monomeric and dimeric cages, the first funding period has delivered a plethora of new data on cage formation, switchable guest uptake, and dynamic behaviour of the systems. Nevertheless, several questions remained open and new ideas and approaches have emerged. The elongation will divide the project into two sub areas: 1. Mechanistic studies of cage formation/dimerization and guest binding as well as synthetic modification of the donor functionalities. In addition, the synthesis of heterobimetallic cages shall be implemented, both via introduction of orthogonal donor sites as well as via application of kinetic effects. 2. The elaborated principles on cage formation, stability, guest binding, mechanical transformation and ligand-centred derivatisation will be applied in the form of functional systems. We have selected three major goals: a) Synthesis of amphiphilic cages, carrying long, if necessary branched, chains of different polarity in equatorial and/or terminal positions and examination of their aggregation behaviour and material properties in solution and bulk compounds. b) Extension of the (spectro-)electrochemical characterization of cages based on redox active ligands (e.g. oligothiophenes, methylene blue, fuchsone ...) aimed at finding further suitable redox pairs for the light-induced charge separation. c) Further studies on the assembly of chiral cages and their propensity for enantioselective guest binding and effect on chemical reactions.

• DFG Programme: Research Grants