Organometallic chemist, and cosmopolitan Bavarian patriot.
Ernst Otto Fischer belonged to the generation robbed of its youth by the Nazi regime. His bitter experiences on the Russian front in the Second World War had a powerful influence on the liberal and cosmopolitan sentiments of a scientist who dedicated his career to fundamental research. He died aged 88 on 23 July in Munich, where he had lived and worked all his life.
Following his return from war, Fischer studied the chemistry of organometallic complexes under Walter Hieber at Munich's Technische Universität. He and his fellow students had initially to rebuild the badly bombed institute with their own hands. Fischer earned his doctorate there in 1952, with an experimental thesis on a simple synthesis process for the versatile reagent tetracarbonylnickel.
But the spur to become a research chemist came from his father, a physics professor, who drew his attention to a 1951 article in Nature on a new type of organo-iron compound known as ferrocene (or 'dicyclopentadienyliron'). Fischer was sceptical of the bivalency of iron proposed in the paper to explain the compound's structure. Together with Wolfgang Pfab, he used X-ray diffraction to determine its true structure, in which two five-sided carbon rings sandwich a core of a single iron atom. This forms an especially stable compound, with an electronic structure similar to that of a noble gas.
The British chemist Geoffrey Wilkinson had independently come across the same sandwich-compound structure for ferrocene. These were moments of glory that heralded a renaissance of inorganic chemistry. There has been a steady stream of compounds combining metals and organic ligands ever since, with novel structures, reactivities and applications in catalysis. Fischer followed his initial achievement soon afterwards (in 1955) with the discovery of a similar structure, dibenzenechromium, that comprised two six-sided carbon rings sandwiching a chromium atom. This discovery was based purely on theoretical considerations and was made together with his extraordinarily gifted student Walter Hafner.
In the face of strong and not always harmonious competition from Wilkinson (who was initially based at Harvard University, and then at Imperial College in London), Fischer's Munich laboratories produced a host of new organometallic compounds in the years that followed. These included the first compounds with metal–carbon double bonds ('carbenes', discovered together with Alfred Maasböl in 1964) and metal–carbon triple bonds ('carbynes', with Gerhard Kreis in 1973). Whereas Wilkinson became interested at an early stage in the catalytic effects of these organometallic materials (such as the use of rhodium complexes to catalyse hydrogenation and oxosynthesis reactions), Fischer focused exclusively on investigating the rich structures and reactivities of the new world of organometallic chemistry. The two shared the Nobel Prize in Chemistry in 1973.
The long-term influence of Fischer's extensive experimental work is impressive, and has opened up new horizons, also extending to practical applications. The best example is the technique of 'olefin metathesis', in which bonds between organic building-blocks are redistributed to produce new products useful in medicine and industry. The catalysis cycle of this process involves the formation of a metal–carbene intermediate. Without Fischer's original research, this advance — which culminated in the Nobel prize awarded to Yves Chauvin, Robert Grubbs and Richard Schrock in 2005 — would not have been possible.
Throughout his life, Ernst Otto Fischer remained deeply attached to his native Bavaria and his home city of Munich. Following his first, brilliant individual research results on ferrocene and similar organometallic complexes, he moved in 1957 to the city's Ludwig-Maximilians-Universität. In 1964, he returned to take the chair of his own mentor, Walter Hieber, at the Technische Universität, a position he held for 20 fruitful years.
Fischer's special talent was to radiate delight in all things new, a trait that served to motivate and inspire his charges. A bachelor throughout his life, he regarded the members of his research group as his family. Once he had established their competence — and he had an unerring instinct for young talent — he granted them unlimited scope to unleash their creativity. In this way, all the researchers who clustered around him in Munich, more than 200 in total, felt a personal responsibility for the common cause.
Shaped in this way, Fischer's students became role models in their turn, shouldering responsibility for the community, passing on knowledge and creating new levels of accountability among an ever-expanding group of researchers. More than a dozen of his postdoctoral students were awarded chair professorships at German universities, and many of his alumni later rose to the higher echelons of the chemical industry.
The contributions of Fischer's protégés to basic and industrial research has been just as significant. A particularly fitting example is the Wacker process to produce acetaldehyde. This uses an ingeniously simple catalytic conversion technique based on ethylene, oxygen and water, and was devised by Walter Hafner together with another of Fischer's former students, Reinhard Jira.
Beyond the realm of chemistry, Ernst Otto Fischer was a highly erudite man who captivated his international colleagues with his profound knowledge of literature and music. He could be both impulsive and contemplative, emollient and combative, and coupled a love of his country with a cosmopolitan outlook — seemingly contradictory traits that found their human symbiosis in him. For colleagues such as myself, he was the epitome of the contentious, relentless fighter for the freedom of science, who fiercely rejected any manipulative outside influences. He was the grand old man of fundamental research, who would settle for nothing less than creativity and scientific curiosity.
With his death, his Bavarian homeland has lost one of its most illustrious sons. He found his final resting place in the Old Cemetery in Munich-Solln on 26 July 2007.