Stimuli-responsive Supramolecular Flowers
Nature exploits stimuli-responsive materials and supramolecular forces to control the assembly of molecules into living organisms, including shaping DNA strands into the double helix structure and building the membrane of every cell. Borrowing this concept from biology, we have designed specific supramolecular containers that can open and close reversibly in a controlled manner – just like the petals of a flower in sunlight. These supramolecular flowering structures will be assembled from two different metal centres that are connected by bridging petal ligands. The petals will be opened and closed reversibly by external stimuli, such as redox processes, pH change or light. The structural changes of the supramolecular flowers will be exploited to turn on (and off) catalytic processes or bind and release selected molecules including drugs targeted to tumour tissue. The development of these new switchable bio-inspired supramolecular architectures will open the way for new applications in catalysis, drug development and materials science.
Interested in this project?
We are currently seeking expressions of interest for three PhD Scholarships from highly motivated PhD candidates with a high level Bsc(Honours) or Masters qualification in Chemistry. The Marsden-funded projects include the cost of fees and provide a full stipend for three years. Two of the students will be based at the University of Auckland (supervised by Profs. Christian Hartinger and James Wright) and the third will be at the University of Otago (A/Prof. James Crowley).
Project 1 (Auckland): Synthesise and characterise 2-petal supramolecular flowers based on ferrocene and explore the suitability of different ligands and combinations of metals to obtain stimuli-responsive systems. The PhD student will be assaying the release of cisplatin from a cage as a model system and will study the impact of cisplatin encapsulation on the biological activity and cell accumulation in a small set of cancer cells.
Project 2 (Otago): Development of the 4-petal Pt-containing supramolecular flowers varying the types of petals coordinated to the Pt centre and a second metal centre. The student will investigate the suitability of the obtained supramolecular flowers for switching, drug delivery (cisplatin) and catalysis, with a particular focus on Pd, Ru and Co-catalysed reactions.
Project 3 (Auckland): Preparation of different cage compounds built from 3 petals, particularly with an emphasis on Co and Fe as the metal centres. The student will explore the dynamics of the opening and closing of the cage compounds using fluorophore encapsulation and spectroscopic methods, and the role in catalysis of such a process.