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Year:
1997
| Volume: 5
| Issue: 3
| Pages: 107-108
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Commentary |
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NOBEL PRIZE FOR CHEMISTRY IN 1996: MOLECULE C60
Mirjana VOJINOVIC-MILORADOV |
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DOI:
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Abstract: |
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Nobel Prize for chemistry in 1996. was awarded to three scientists: Harold Kroto (Sussex University, England), Richard Smalley (Rice University, USA) and Robert Curl (Rice University, USA), for the discovery of C60 ("buckyball"). They led the American-English research team who by mere serendipity using high-powered laser synthesized this molecule as the perfect point symmetry form ever discovered in the nature. The newly derived form, consisting of 60 carbon atoms arranged in the network of 12 pentagons and 20 hexagons on sphere surface (as a soccer-ball), is the third carbon form (beside graphite and diamond).
Long carbon chains and their vibration-rotation dynamic have attracted Kroto (Harold Kroto, born in 1939, Wisbech, Cambridgeshire, England) since 1975, when he started researches into molecules HC7N and HC7N in interstellar space. It was not until 1980, however, that he obtained experimental evidence which confirmed that ion-molecule reactions in the universe could create such forms. Since that time, Kroto has started considering the possible laboratory research in interstellar carbon dust stimulations. Having been invited by his colleague and his friend, Professor Curl (Robert Curl, born in 1933, Alice, Texas), Kroto came to Rice University in 1984 where he met professor Smalley (Rick Smalley, born in 1943, Akron, Ohio, USA). Professor Smalley was just engaged in the synthesizing of new materials by laser. Besides other results, Smalley discovered an unusual molecule, SiC2 which was not of linear, but ring type. Kroto suggested, on that occasion, that they should carry out an experiment together in which they would perform a laser synthesis of graphite derived carbon molecules.
In August 1985, preparations for the experiment were approaching their end. Having accepted Curl's invitation, Kroto came to Rice University again, in order to start the joint experiment. The experiment began on September, 1st 1985, and researches progressing, it soon became obvious that something curious was happening. Everything indicated that there was some carbon molecule form consisting of 60 atoms, but of unknown order. Five-day experiment having been completed, the research team members concluded that the derived molecule should be sphere in its form, since the NMR specter of the obtained carbon structure showed only one peak. This implied that all the carbon atoms in the structure were equal and that they were located on the sphere surface with the same charge density. But, what the real order of atoms on the sphere surface is, was a real enigma to them at that time, and they needed seven days to solve the mystery. They were trying for days to close the sphere surface by hexagon benzene rings, but in vain. Who knows how long they would search for the answer, when suddenly became clear to them that the key word searching for was pentagon. As a matter of fact, Kroto recalled to his mind Buckminster Fuller who had been using not only hexagons, but pentagons as well in order to construct a geodesy dome with an optimal ball structure (minimal material costs - maximal stability) for the American pavilion at EXPO'67 in Montreal. Kroto remembered while having spent time with his children's a couple of years ago, that he had been making Fuller's geodesy dome of paper as childrens school task. If the nature uses optimization while forming structures , than pentagons could be carbon spherical cluster elements, Kroto reasoned. In order to prove this hypothesis, Smalley would, after exhausting working days, cut pentagons and hexagons of paper during the night. On September, 13th, 1985 he made a model of truncated icosahedron, symmetrical and very stable one. He said the that in those days he genuinely felt the power and the beauty of the nature's simplicity.
Five more research groups, however, were exploring C60, independently one of others. The Japanese research group (Yoshida-Osawa) predicted this molecule as far back as 1970, while Iijima synthesized it in 1980, although he was not even aware of it. Something similar occurred with the American-German research team (Huffman-Kratschmer) who had been working on investigations in reflection of light phenomenon in the environment which resembled the interstellar dust space. They derived carbon dust similar to interstellar one, not knowing until 1990 that it contained approximately 14% of C60 molecule. The Russian research team (Bochvar-Galpern) according to physical chemical calculations anticipated the possibility of the existence of this molecule in 1972. They published their paper on the calculation of the energetic conditions of C60 molecule at the Russian Academy of Science, but it went unobserved. The research group (Kaldor Cox) of the famous American company, Exxon, in search of new power sources, which could replace petrol and oil, synthesized the whole carbon cluster family in 1984, molecule C60 being the most famous member, but they did not provide the appropriate explanation of their own experimental results. Trying to discover suitable materials for molecular computers the Yugoslav-American research group (Koruga Hameroff) as for back as 1978 pointed to the solutions that the nature had effected on molecular level in biology. The structures they wore researching as intelligent cellular molecules (clathrin and microtubules) from an aspect of their symmetry are identical to C60 molecule and carbon nanotubes. On the bass of the findings from biology regarding these strucures the research group Koruga-Hameroff suggested in 1984 designing of molecular carbon devices, but owing to the "realm of silicon" these suggestions were not taken into consideration. The above mentioned research team was the first to make STM picture of C60 molecule at Molecular machines Research Center at the University of Belgrade, in 1992 and in 1993 "Fullerene C60: History, Physics, Nanobiology, Nanotechnology" was published by a famous publishing house Elsevier, as the first book on the subject.
It is estimated that this molecule (C60), as well as the whole family of carbon clusters known as "Fullerenes and carbon nanotubes", will be one of the strategic issues in the 21st century. Their application as new materials is being expected in electrical power sources, telecommunications, computers, biomedicine, superconductors, mechanical engineering, etc. It is believed that for some scientific technological solutions based on C60 and its clusters one or even more Nobel prizes could be awarded. |
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Key words:
Molecule C60 |
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