Research area A: Adaptive molecular systems
A01 New photoswitches for integration in adaptive nanosystems
Molecular photoswitches are versatile sensors and actuators for the development of intelligent matter. In this project we will design and prepare azo and spiropyran photoswitches as building blocks for the assembly of adaptive nanosystems. The project combines our expertise in the development of innovative photoswitches and surface ligands based on N-heterocyclic carbenes. These photoswitches will be immobilized on nanoparticles and patterned on surfaces using soft lithography. Furthermore, the photoswitches developed in this project will be integrated in a range of adaptive molecular systems, soft materials and solid-state nanosystems explored in the CRC.
A02 Control of the primary and secondary structure in synthetic polymers to access adaptive soft materials
Prof. Dr. Armido Studer - Organic Chemistry Insitute
Methods for the alternating controlled radical copolymerization to access alternating ABC-type copolymers will be developed. Unique self-assembly behavior is expected for these soft materials. Adaptive materials using mechanophores as active functionalities will be prepared. Mechanical stress will alter the stiffness or the absorption properties in these materials. A second research line is devoted to the preparation of chiral rigid polymers with defined secondary structure by using anionic ring-opening polymerization of chiral donor-acceptor cyclopropanes. Chiral polymers bearing redox-active Ru-functionalities at their side chains will be synthesized and the material will be tested as a self-oscillating system where a defined periodical structural change is achieved and maintained in the presence of a chemical fuel.
A03 Interfacing self-assembly and multiple stimuli to create adaptive behaviour
Controlling the energy landscape of stimuli-responsive supramolecular materials remains a major challenge in the field of self-assembly. In this project, we aim at unravelling the effect of various triggers on supramolecular polymerization by detailed mechanistic insights. By interfacing supramolecular polymerization under controlled experimental conditions and a given stimulus, we will switch from responsive to adaptive behaviour on demand. The sequential application of multiple stimuli at defined intervals is expected to produce unprecedented functional supramolecular materials with oscillating, adaptive, sensing and memory behaviour.
A04 Developing tunable triplet emitters towards adaptive electroluminescent materials
Light-emitting materials composed of photoluminescent metal-organic coordination compounds attached to metal nanoparticles or embedded in soft polymeric matrices will be developed. They will be controlled by and adapt to a variety of external stimuli such as light, temperature, pressure, mechanical force, and electrochemical potential. In turn, these features will enable them to act as sensors of environmental changes. In the long term, the developed concepts will enable color-coded information storage and processing by embedment in nanophotonic matrices and integration into neuromorphic architectures.
A05 Light-controlled anion-binding adaptive supramolecular systems
Photo-responsive azobenzene-triazole systems will be designed to allow Z-selective anion binding, resulting in photo-reversible switchable anion availability and catalytic activity. Peptide functionali-zation will enable supramolecular aggregates, with anion binding constants depending on the available space for isomerization and thus on the aggregation state. As a route towards adaptive materials we envision to implement memory by modifying aggregate structures based on the steric requirement of the azotriazole E and Z forms during repeated photoisomerization cycles. The ultimate goal is to construct materials with memory-controlled photo-responsive anion binding properties.
A06 A semi-synthetic nanosystem for programmable control of output based on rational design and directed evolution
Prof. Dr. Andrea Rentmeister - Institute of Biochemistry
In the first funding period, we will develop a system that senses different small molecules and actuates the formation of an output signal. The semi-synthetic nanosystem consists of a reaction network in aqueous solution and explores different feedback mechanisms to move from a responsive to an adaptive system that self-regulates the formation of metabolites, RNA, or protein and leads to a detectable output signal (e.g. fluorescence, enzymatic activity or proteinaceous material). Permanent or light-removable modifications of DNA will be tested as a molecular memory indicating which fuels the system has previously been exposed to. The long-term goal of this project is to realize adaptive behavior and learning capability, reminiscent of artificial synapses, by integrating this sensing-actuation system into photonic circuits or confined spaces, such as vesicles and nanofabrication approaches, and to be able to distinguish experienced systems from naïve ones.