In 1991, organic chemist Sir Fraser Stoddart, who has died aged 82, built artificial molecular machines for the first time. It mimics the way some biological materials are able to move in an interlocking, almost mechanical way.
Stoddart had previously pointed out the existence of natural organic molecules such as protein MyosinWhich stimulate muscle contraction, or motor enzymes that help maintain DNA, work like little machines. He realized that the molecular components of these machines, such as gears, pistons and switches in large-scale machines, could move relative to each other and, more importantly, could be linked together mechanically and become interlocked. By constructing their artificial equivalents, powered by electrical energy, chemical reactions, or light, he created an entirely new field in organic chemistry.
The first machine, which he named A RotaxaneIt consists of a ring-shaped molecule attached to a longer molecule that acts as a hub. More complex molecular machines, created by Stoddart and other chemists following in his footsteps, would follow, including the successful synthesis Catenanis – Two intertwined molecular rings. His work bridged the gap between the chemistry and engineering challenges of working on the very small scale of nanoscale electrical systems, and expanded the field of supramolecular chemistry – the branch of chemistry outside of the particle.
Molecular machines are manufactured using specialized equipment, with techniques such as scanning tunneling microscopy and X-ray crystallography used to validate the structures, function and efficiency of the artificial molecular machines they manufacture.
These machines expanded the potential applications for Nanotechnology. Innovations such as molecular elevators (nano-sized devices that transport molecules across cell membranes) and computer memory chips smaller than a white blood cell but with a memory storage capacity of up to 160,000 bits all benefited from Stoddart’s initial work, as did emerging medicine. Nanobot technology.
For his initial discoveries and subsequent research in this field, Stoddart received an award Nobel Prize in Chemistry 2016He shared it with the Dutch organic chemist Ben Feringa and the French coordinating chemist Jean-Pierre Sauvage.
Born in Edinburgh, Freezer He was the only child of Jane (née Jane Fortune) and Thomas Stoddart, who were farmers. He grew up in Edgelow Farm, Midlothian, a small community dozens of miles south of the Scottish capital, and had no electricity for the first 18 years of his life. At the local primary school in Carrington, his teachers encouraged his love of building Meccano toys, to which he later attributed his professional interest.
He won a scholarship to Melville College, one of Scotland’s leading independent schools, and in 1960 he went to the University of Edinburgh, where he studied chemistry, physics and mathematics. After obtaining a bachelor’s degree (1964) in chemistry, he remained in Edinburgh, researching the natural gum of acacia trees for his doctorate (1966).
After appointments at Queen’s University in Ontario, Canada, and the University of Sheffield, he began working in 1978 in the laboratory of the ICI Chemicals Group in Runcorn, Cheshire, where he began researching mechanically cross-linked chemicals, a passion that would come to define his academic career.
Among a series of academic appointments, the most important were his position as Reader (1982-1990) and then Professor of Organic Chemistry at Birmingham (1990-1997), where he began his pioneering work in the field of molecular machines. at the University of California, Los Angeles (1997-2007); And his management of the center chemistry Integrated Systems at Northwestern University in Illinois (2008-23).
His academic papers were distinguished by their cartoon-like form of presentation, eschewing the more common formal written method of standardized, color-coded diagrammatic representations of molecular properties. This method has been adopted by other researchers in this field.
Stoddart was a strong believer in the importance of removing all barriers to the free movement of students and researchers. He repeatedly stated that “science is universal; Science knows no boundaries.” He also expressed his belief that global warming represents the greatest threat to humanity, adding that “the Nobel Prize was modest but it means nothing if what you do does not benefit society.”
Then, having realized the potential of hydrogen as a clean, efficient, combustible fuel, in 2021 he co-founded a California-based startup with Samer Taha and Omar Yaghi in 2021. H2MOFdedicated to solving the challenges associated with hydrogen storage and transportation. A few months before his death, Stoddart published in the journal Nature Chemistry a nanomaterial with a high hydrogen storage density, indicating the potential for major progress in this field.
Stoddart was often outspoken and disrespectful of the bureaucratic processes of many of the institutions in which he worked, and he expressed opinions that often brought him into conflict with their academic rigidity and administrative requirements. However, he was determined to share his knowledge, and over the last 35 years of his life he trained more than 500 doctoral students in his laboratories.
He was knighted in 2006, and has received the Albert Einstein World Science Prize (2007) and the Royal Society of Chemistry Centenary Prize (2014). He was elected a Fellow of the Royal Societies of London and Edinburgh, winning the Davy Medal for the former in 2008 and the Royal Medal for the latter in 2010. He was also a member of the US National Academy of Sciences.
In 1968 he married Norma Shulan, a biochemist. She died in 2004, leaving behind their two daughters, Fiona and Alison, and five grandchildren.
