Discovery of the fullerenes

In 1984 it was observed that, upon laser vaporization of graphite, large carbon-only clusters C with u = 30-190 can be produced [14]. The mass distribution of these clusters was determined by time-of-flight mass spectrometry. Only ions with 

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The Nobel prize in Chemistry for the year 1996 was awarded for the discovery of the fullerenes, the third allotropic form of carbon, with Cgo and C70 as the two most prominent representatives. While the fullerenes of course are the epitome of carbon-rich molecular compounds, it is an irony that their synthesis is more of a physical phase transition, taking place under drastic conditions [1]. 

Concept With the discovery of the fullerenes, it has become evident that elemental carbon can exist in almost an infinite number of stable allotropes that are either molecular or polymeric in nature. Whereas achiral and chiral fullerenes can now be prepared in bulk quantities and methods for their regio- and stereoselective multiple functionalization are being developed in increasing numbers, the... 

Abstract The past two decades have profoundly changed the view that we have of elemental carbon. The discovery of the fullerenes, spherically-shaped carbon molecules, has permanently altered the dogma that carbon can only exist in its two stable natural allotropes, graphite and diamond. The preparation of molecular and polymeric acetylenic carbon allotropes, as well as carbon-rich nanometer-sized structures, has opened up new avenues in fundamental and technological research at the interface of chemistry and the materials sciences. This article outlines some fascinating perspectives for the organic synthesis of carbon allotropes and their chemistry. Cyclo[n]carbons are the first rationally designed molecular carbon allotropes, and... 

Shortly after the discovery of the fullerenes in 1985 (Kroto et al., 1985) and especially after their accessibility in macroscopic quantities (Kraetschmer et al., 1990) these new carbon allotropes raised great interest in the chemical world due to their unique structural and electronic properties. As a direct consequence of the curved conjugated n-systcm fullerenes were predicted to be fairly electronegative with the... 

It is therefore the right time to give a first comprehensive overview of fullerene chemistry, which is the aim of this book. This summary addresses chemists, material scientists and a broad readership in industry and the scientific community. The number of publications in this field meanwhile gains such dimensions that for nonspecialists it is very difficult to obtain a facile access to the topics of interest. In this book, which contains the complete important literature, the reader will find all aspects of fullerene chemistry as well as the properties of fullerene derivatives. After a short description of the discovery of the fullerenes all methods of the production and isolation of the parent fullerenes and endohedrals are discussed in detail (Chapter 1). In this first chapter the mechanism of the fullerene formation, the physical properties, for example the molecular structure, the thermodynamic, electronic and spectroscopic properties as well as solubilities are also summarized. This knowledge is necessary to understand the chemical behavior of the fullerenes. 

Soon after the discovery of the fullerenes it was suggested that these or particles of similar nature, could be related to one of the most intriguing problems of astrophysics the diffuse interstellar bands discovered more than eight decades ago, but not yet explained, and with the ultraviolet band centered in 2,175 A, which is the most intense band in the interstellar medium discovered more than 30 years ago. The origin of the UV bump is attributed to carbon particles of small size whose characteristics are not yet conclusively established. 

Before 1985, six crystalline forms of carbon were known two forms of graphite, two forms of diamond, and chaoit and carbon (VI) discovered in 1968 and 1972, respectively. In addition a number of almost pure amorphous forms exist, such as polyacetylene (7.60) and cumulene (7.61) and recently a number of interesting nanostructured forms of carbon have been produced (Section 15.8). The year 1985 marked the discovery of the fullerenes, which represent the only truly pure molecular form of carbon, are produced under very extreme conditions as carbon vapour condenses in an atmosphere of an inert gas such as helium. Harold Kroto s interest in this chemistry originated with microwave spectroscopic studies of the atmosphere of stars and interstellar dust clouds. Kroto wanted to try to reproduce in the laboratory spectra of carbon... 

The discovery of the fullerenes was received with a mixture of enthusiasm and hostility. The molecules existed only in the mass spectrometer and some researchers were dubious. Final proof came in 1990 with the isolation of macroscopic amounts of C60. This allowed the 13C NMR spectrum of the compound to be recorded. As predicted, it proved to be a single line (at 6 143 ppm) - all of the carbon atoms in C60 are equivalent. 

The discovery of the fullerene molecule was very exciting to chemists. They had never seen a molecule like it. They have been studying ways of working with this molecule. One interesting technique has been to cut open just one small part of the molecule. Then they cut open a small part... 

Returning to the question which motivated the experiments which in turn led to the discovery of the fullerenes do such carbon clusters exist in nature Astronomical searches for the distinctive fullerene signature of infrared absorption lines have been unsuccessful, and laboratory spectra of fullerenes have not shown any explicit connection to unsolved as-trophysical problems such as the so-called diffuse interstellar bands or other unidentified spectral features.[Ha92]... 

As early as 1980, even before the discovery of the fullerenes, that is, S. lijima reported on the preparation of multilayered, spherical particles of graphitic character. He conceived them to be an sp sp -hybrid material, and his results went largely unnoticed. The structures described then were first interpreted as carbon onions only after the determination of the fuUerenes structure and after D. Ugar-te s finding that particles of fullerene soot may be transformed into multilayered fullerenes by electron irradiation (Figure 4.1). 

The development of the chemistry of the fullerenes was and continues to be a most exciting challenge in chemical research of the 1990s. It is not only the symmetrical structure and the beauty of these molecular allo-tropes of carbon but also their unprecedented properties that keep a large number of chemists, physisists and material scientists working with these spherical architectures. It came as no surprise that, the discovery of the fullerenes by Curl, Kroto and Smalley was rewarded with the Nobel prize in 1996. 

Smalley in the 1980s and led to the discovery of the fullerenes (see e.g. Kroto et al (1985)), which was recognized by awarding the 1996 Nobel Prize in Chemistry to Kroto, Curl and Smalley. 

A good deal of the excitement surrounding the discovery of the fullerenes was their perceived potential as novel materials for a number of applications. Early speculations suggested that the essentially spherical structure of Cm might be the basis of novel lubricants, providing "molecular ball bearings". However, the first hint of special properties came in 1991 when a group at Bell Labs reported superconductivity at 18 K in a sample of Cm that... 

Discovery Graphite and diamond were known to ancient civilizations. Carbon as soot and charcoal was used in prehistoric time. The discovery of the fullerenes is new (1985) and led to a Nobel Prize in 1996. 

The Discovery of the Fullerenes. In experiments carried out at Rice University in 1985 associated with the presence of carbon in stars and space [Kroto HW, Heath JR, O Brien SC, Curl RF, Smalley RE (1985) Nature 318 162], the Ceo molecule was discovered. This species is one of the many carbon clusters which can be generated when a plasma of carbon vapor produced in the surface of graphite by laser irradiation is cooled by an inert gas jet. The detection of this type of carbon aggregate which appears to constitute a third allotropic and the first molecular form of carbon by mass spectroscopy is illustrated in Fig. 4.18. 

Ever since Curl, Kroto, and Smalley were awarded the Nobel Prize for their discovery of the fullerenes, I open the oral exam for the bachelor in organic chemistry with the question How many allotropes of carbon are there The upright student will give Three as an answer, but the good one will say At least three . In fact, the number of conceivable scaffolds that can be constructed with this basic building block is endless just take a piece of paper and your carbon-filled pencil On the other hand, that this question is new in organic chemistry, can be maintained only by those who know little about the history of our discipline. 

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