Vol'pin came from a medical background but, after service during the Second World War, he graduated in Chemistry from Moscow State University in 1949. He first became well-known in the West in the mid-1950s for his studies on the chemistry of tropylium, a remarkable organic compound with seven carbons in a ring, bearing a positive charge, which was isolable due to its 6-electron "aromatic" character. Despite this relative stability it was still highly reactive, and indeed Vol'pin was badly injured during experiments with the perchlorate salt.
He later expanded the chemistry of such organic positively charged ions to the 3-membered ring, 2-electron analogues. For that work he was awarded the Lenin Prize in 1963. Deriving from this he became interested in the highly reactive unsaturated single carbon species called carbenes, which in turn led him to investigate related systems, including some highly reactive and unsaturated metal complexes.
An interesting sidelight on the path of pure scientific research in the hands of a master like Vol'pin is seen in his progression from organic chemistry to a most remarkable discovery in inorganic chemistry: a metal complex with the ability to "fix" atmospheric nitrogen under very mild conditions. Nitrogen itself is a major inert component of the air we breathe. By contrast, compounds in which nitrogen is fixed, such as amino acids, ammonia, and nitrates, are reactive substances and form a vital part of both biological and commercial-industrial life.
The only previous ways to fix nitrogen - in other words to turn it from an inert gas into a useful substance - were biological, which had severe limitations, or by the use of very high temperatures and extreme conditions. The catalytic system that Vol'pin and V.B. Shur developed offered a signpost to many other workers. For this research Vol'pin was awarded the USSR State Prize in 1982, as well as numerous other honours, and was elected to full membership of the USSR Academy of Science in 1987.
In his later work he studied biological metal complexes that could generate very active species, in this case free radicals. The object of these researches was to find compounds that were absorbed by tumours and would destroy them without harming healthy tissue. He felt that this work represented his most satisfying achievement.
In 1980 he was invited to Britain as Centenary Lecturer of the Royal Society of Chemistry. This journey was a major event as the Soviet authorities made it extremely difficult for scientists in general, and Jewish ones in particular, to visit their western counterparts.
In 1979 the Portuguese Academy had invited Vol'pin to attend a major conference on nitrogen fixation in Lisbon. Vol'pin did not arrive at the opening and when the organiser enquired where he was, he discovered that the officials at the USSR Academy had not seen fit to process the travel application. The President of the Portuguese Academy, a retired general, made sure that a loud and clear message got through from the Portuguese Embassy in Moscow to the USSR Academy of Sciences. Travel documents were issued immediately and Vol'pin arrived in Lisbon late but still in time to meet and address his colleagues. Against that background it was indeed surprising that he managed to come to Britain as Centenary Lecturer, and only a year late.
Unfortunately his tribulations at the hands of the Soviet bureaucracy continued. In 1984 he left the final banquet of the International Symposium on Homogeneous Catalysis in Leningrad with a jaunty step on his way to a conference in France. However, he never got there, and when he reappeared in Moscow some days later he would not comment on what had happened in the interim. One didn't ask too many questions; even in 1984 these were everyday problems. Hindsight today suggests that it was the intolerance of the Communist system towards any independent- minded person, rather than his Jewish origins, that caused even a wholly non-political man like Vol'pin to suffer.
Vol'pin was a tall youthful-looking man with a ready smile. He was always cheerful and had a warm firm handshake, even though he had lost several of his fingers in an explosion. He was a most convivial companion, and much enjoyed entertaining friends and visitors. He greatly appreciated cultural events, theatres and concerts, but also good food, dancing and the occasional vodka; indeed, under his tutelage the foreign visitor soon learnt to offer toasts to "Anglo-Russian friendship", to "scientific understanding", and especially to "the ladies" present.
In his later career he was the intellectual powerhouse that drove the research staff of INEOS by example and inspiration. Characteristically he ran a relatively small group himself and did not have his name on all the Institute publications, as was the custom elsewhere. He was a very approachable, gentle and nice man; and he was appointed Director on three separate occasions.
Mark Efimovitch Vol'pin had a long and happy marriage to the distinguished biochemist, Svetlana Mikhailovna Avaeva - their two children, Olga Mikhailovna and Igor Mark-ovich, are also scientists.
Mark Efimovitch Vol'pin, chem-ist: born Simferopol, Soviet Union 23 May 1923; married Svetlana Mikhailovna Avaeva (one son, one daughter); died Moscow 26 September 1996.