|Date||05 May 2023|
|Time||2:30 pm – 3:30 pm (HKT)|
|Venue||Lecture Theatre P1, Chong Yuet Ming Chemistry Building|
|Speaker||Prof. J. Fraser Stoddart|
Department of Chemistry
Artificial Molecular Machines
Date: 5 May 2023 (Fri)
Time: 2:30 pm – 3:30 pm (HKT)
Venue: Lecture Theatre P1, Chong Yuet Ming Chemistry Building
Prof. J. Fraser Stoddart
Department of Chemistry
Fraser Stoddart, 2016 Nobel Laureate in Chemistry, was born in Edinburgh, Scotland, in 1942. He obtained all his degrees from Edinburgh University and spent time at Queen’s University, Imperial Chemical Industries and the Universities of Sheffield and Birmingham in the UK before moving to UCLA in the US in 1997. He has mentored over 500 undergraduate and graduate students and postdoctoral fellows during his career, has over 1250 publications, and is presently a Board of Trustees Professor of Chemistry at Northwestern University. Stoddart was honored by Her Majesty Queen Elizabeth II as a Knight-Bachelor in her 2007 New Year’s Honors List for his services to chemistry and molecular nanotechnology. He was one of the recipients in 2016 of the Nobel Prize in Chemistry for the design and synthesis of molecular machines.
In 2010, we discovered an example of radically enhanced molecular recognition, which represents a valuable tool for the design and synthesis of artificial molecular pumps (AMPs) and artificial molecular motors. In my lecture, I will describe how this breakthrough has led to the fabrication of (1) two AMPs, (2) a dual and a duet pump, (3) a precise polyrotaxane synthesizer, which can be produced by attaching an AMP – call it a pumping cassette – to each end of a polymeric connecting chain, (4) an electric molecular motor based on a catenane, and (5) mechanisorption, which results from non-equilibrium pumping to form mechanical bonds between adsorbents and adsorbates. This active mode of adsorption has been realized on surfaces of metal-organic frameworks (MOFs) grafted with arrays of molecular pumps. Adsorbates are transported from one well-defined compartment – the bulk – to another well-defined compartment – the interface – thereby creating large potential gradients in the form of chemical capacitors wherein energy is stored in metastable states.
All these molecular pumps operate away-from-equilibrium, using energy ratchet mechanisms, in the presence of fuels and in environments that are dominated by Brownian motion. It is possible, in principle, to generate highly engineered polyrotaxanes with palindromic arrays of co-constitutionally heterotopic rings positioned on constitutionally symmetrical polymer dumbbells and then, ultimately, transcribe their programmed information back into the domain of sequence-controlled polymer synthesis. Mechanisorption extends the scope and potential of adsorption phenomena and interfaces. If materials scientists can incorporate mechanisorption into other active structures, the storage of gases like hydrogen, carbon dioxide and methane will enter a whole new world.
- ALL ARE WELCOME -