Azafullerene

Last updated March 12, 2019

Azafullerenes are a class of heterofullerenes in which the element substituting for carbon is nitrogen. They can be in the form of a hollow sphere, ellipsoid, tube, and many other shapes. Spherical azafullerenes resemble the balls used in football (soccer). They are also a member of the carbon nitride class of materials that include beta carbon nitride (β-C3N4), predicted to be harder than diamond. Besides the pioneering work of a couple of academic groups, this class of compounds has so far garnered little attention from the broader fullerene research community. Many properties and structures are yet to be discovered for the highly-nitrogen substituted subset of molecules.

Heterofullerenes are classes of fullerenes, at least one carbon atom is replaced by another element. Based on spectroscopy, substitutions have been reported with boron (borafullerenes), nitrogen (azafullerenes), oxygen, arsenic, germanium, phosphorus, silicon, iron, copper, nickel, rhodium and iridium. Reports on isolated heterofullerenes are limited to those based on nitrogen and oxygen.

Carbon Chemical element with atomic number 6

Carbon is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Three isotopes occur naturally, ¹²C and ¹³C being stable, while ¹⁴C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity.

Nitrogen Chemical element with atomic number 7

Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name azote, from the Greek ἀζωτικός "no life", as it is an asphyxiant gas; this name is instead used in many languages, such as French, Russian, Romanian and Turkish, and appears in the English names of some nitrogen compounds such as hydrazine, azides and azo compounds.

The first fullerene molecule to be discovered, and the family's namesake, buckminsterfullerene (C₆₀), was prepared in 1985 by Richard Smalley, Robert Curl, James Heath, Sean O'Brien, and Harold Kroto at Rice University.^[1] A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, tube, and many other shapes. Spherical fullerenes are also called buckyballs, and they resemble the balls used in football (soccer). Fullerenes are similar in structure to graphite, which is composed of stacked graphene sheets of linked hexagonal rings; but they may also contain pentagonal (or sometimes heptagonal) rings.

A fullerene is an allotrope of carbon in the form of a hollow sphere, ellipsoid, tube, and many other shapes and sizes. Spherical fullerenes, also referred to as Buckminsterfullerenes or buckyballs, resemble the balls used in association football. Cylindrical fullerenes are also called carbon nanotubes (buckytubes). Fullerenes are similar in structure to graphite, which is composed of stacked graphene sheets of linked hexagonal rings. Unless they are cylindrical, they must also contain pentagonal rings.

Buckminsterfullerene is a type of fullerene with the formula C₆₀. It has a cage-like fused-ring structure (truncated icosahedron) that resembles a soccer ball (football), made of twenty hexagons and twelve pentagons, with a carbon atom at each vertex of each polygon and a bond along each polygon edge.

Richard Errett Smalley was the Gene and Norman Hackerman Professor of Chemistry and a Professor of Physics and Astronomy at Rice University, in Houston, Texas. In 1996, along with Robert Curl, also a professor of chemistry at Rice, and Harold Kroto, a professor at the University of Sussex, he was awarded the Nobel Prize in Chemistry for the discovery of a new form of carbon, buckminsterfullerene, also known as buckyballs. He was an advocate of nanotechnology and its applications.

Azafullerenes were first discovered in 1993 and reported in the California State Science Fair.^[2] The derivatives were formed in the gap between two graphite rods connected to an electric power supply. A small air leak led to contamination of the inert atmosphere and the subsequent reaction. The materials can also be formed by chemical reactions on fullerene or laser ablation of graphitic materials.

The California State Science Fair is a science fair held annually at the California Science Center in Los Angeles.

Subsequent work revealed a wide range of carbon nitride structures.^[3]^[4]^[5] Examples include (C₅₉N)₂ (biazafullerenyl),C₅₈N₂ (diaza[60]fullerene), C₅₇N₃ (triaza[60]fullerene) and C₄₈N₁₂. The nitrogen atoms substitute for carbon atoms on the cage-like molecules. Much of the work has been theoretical in nature. The C₄₈N₁₂ molecule was calculated to be an insulator, with the eight all-carbon rings forming regions of extended electron delocalization.^[6]

Carbon nitrides are compounds of carbon and nitrogen.

Related Research Articles

Boron nitride is a heat and chemically resistant refractory compound of boron and nitrogen with the chemical formula BN. It exists in various crystalline forms that are isoelectronic to a similarly structured carbon lattice. The hexagonal form corresponding to graphite is the most stable and soft among BN polymorphs, and is therefore used as a lubricant and an additive to cosmetic products. The cubic variety analogous to diamond is called c-BN; it is softer than diamond, but its thermal and chemical stability is superior. The rare wurtzite BN modification is similar to lonsdaleite and may even be harder than the cubic form.

Sir Harold Walter Kroto, known as Harry Kroto, was an English chemist. He shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for their discovery of fullerenes. He was the recipient of many other honors and awards.

Robert Floyd Curl Jr. is a University Professor Emeritus, Pitzer–Schlumberger Professor of Natural Sciences Emeritus, and Professor of Chemistry Emeritus at Rice University. He was awarded the Nobel Prize in Chemistry in 1996 for the discovery of the nanomaterial buckminsterfullerene, along with Richard Smalley and Harold Kroto of the University of Sussex.

Beta carbon nitride (β-C₃N₄) is a superhard material predicted to be harder than diamond.

Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include diamond and graphite. In recent decades many more allotropes, or forms of carbon, have been discovered and researched including ball shapes such as buckminsterfullerene and sheets such as graphene. Larger scale structures of carbon include nanotubes, nanobuds and nanoribbons. Other unusual forms of carbon exist at very high temperatures or extreme pressures. Around 500 hypothetical 3-periodic allotropes of carbon are known at the present time according to SACADA database.

Sigma bond strongest type of covalent chemical bond; formed by head-on overlapping between atomic orbitals. Sigma bonding for diatomic molecules (using the language and tools of symmetry groups):σ-bond is symmetrical with respect to rotation about the bond axis

In chemistry, sigma bonds are the strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals. Sigma bonding is most simply defined for diatomic molecules using the language and tools of symmetry groups. In this formal approach, a σ-bond is symmetrical with respect to rotation about the bond axis. By this definition, common forms of sigma bonds are s+s, p_z+p_z, s+p_z and d_z²+d_z² . Quantum theory also indicates that molecular orbitals (MO) of identical symmetry actually mix or hybridize. As a practical consequence of this mixing of diatomic molecules, the wavefunctions s+s and p_z+p_z molecular orbitals become blended. The extent of this mixing depends on the relative energies of the MOs of like symmetry.

Endohedral fullerenes, also called endofullerenes, are fullerenes that have additional atoms, ions, or clusters enclosed within their inner spheres. The first lanthanum C₆₀ complex was synthesized in 1985 and called La@C₆₀. The @ (at sign) in the name reflects the notion of a small molecule trapped inside a shell. Two types of endohedral complexes exist: endohedral metallofullerenes and non-metal doped fullerenes.

Endohedral hydrogen fullerene (H₂@C₆₀) is an endohedral fullerene containing molecular hydrogen. This chemical compound has a potential application in molecular electronics and was synthesized in 2005 at Kyoto University by the group of Koichi Komatsu. Ordinarily the payload of endohedral fullerenes are inserted at the time of the synthesis of the fullerene itself or is introduced to the fullerene at very low yields at high temperatures and high pressure. This particular fullerene was synthesised in an unusual way in three steps starting from pristine C₆₀ fullerene: cracking open the carbon framework, insert hydrogen gas and zipping up by organic synthesis methods.

Fullerene chemistry is a field of organic chemistry devoted to the chemical properties of fullerenes. Research in this field is driven by the need to functionalize fullerenes and tune their properties. For example, fullerene is notoriously insoluble and adding a suitable group can enhance solubility. By adding a polymerizable group, a fullerene polymer can be obtained. Functionalized fullerenes are divided into two classes: exohedral fullerenes with substituents outside the cage and endohedral fullerenes with trapped molecules inside the cage.

Strip Algebra is a set of elements and operators for the description of carbon nanotube structures, considered as a subgroup of polyhedra, and more precisely, of polyhedra with vertices formed by three edges. This restriction is imposed on the polyhedra because carbon nanotubes are formed of sp2 carbon atoms. Strip Algebra was developed initially for the determination of the structure connecting two arbitrary nanotubes, but has also been extended to the connection of three identical nanotubes

James R. Heath is an American chemist and the president and professor of Institute of Systems Biology. Previous to this, he was the Elizabeth W. Gilloon Professor of Chemistry at the California Institute of Technology, after having moved from University of California Los Angeles.

Carbocatalysis is a form of catalysis that uses heterogeneous carbon materials for the transformation or synthesis of organic or inorganic substrates. The catalysts are characterized by their high surface areas, surface functionality, and large, aromatic basal planes. Carbocatalysis can be distinguishable from supported catalysis in that no metal is present, or if metals are present they are not the active species.

C₇₀ fullerene is the fullerene molecule consisting of 70 carbon atoms. It is a cage-like fused-ring structure which resembles a rugby ball, made of 25 hexagons and 12 pentagons, with a carbon atom at the vertices of each polygon and a bond along each polygon edge. A related fullerene molecule, named buckminsterfullerene (C₆₀ fullerene), consists of 60 carbon atoms.

Higher fullerenes are fullerene molecules consisting of more than 70 carbon atoms. They adopt cage-like structures made up of the fusion of hexagons and pentagons, with a carbon atom at the vertices of each polygon and a bond along each polygon edge. They are all black solids that dissolve sparingly in organic solvents to give deeply colored solutions.

A buckyball or buckminsterfullerene is a molecule resembling a soccer ball composed of 60 carbon atoms.

Borospherene (B₄₀) is a cluster molecule containing 40 boron atoms. It is similar to buckminsterfullerene, the "spherical" carbon structure, but with a different symmetry. The discovery of borospherene was announced in July 2014, and is described in the journal Nature Chemistry. Borospherene is the latest in a series of cluster molecules, including buckminsterfullerene (C₆₀), stannaspherene, and plumbaspherene. The newly discovered molecule includes unusual heptagonal faces.

References

↑ Kroto, H.W.; et al. (1985). "C60: Buckminsterfullerene". Nature 318 (6042): 162–163. Bibcode : 1985Natur.318..162K. doi : 10.1038/318162a0
↑ D.J. Harris, Discovery of Nitroballs: Research in Fullerene Chemistry, 1993 California State Science Fair, http://cssf.usc.edu/History/1993/S05.html
↑ Hummelen et al, Isolation of the Heterofullerene C59N as Its Dimer (C59N)2, Science 269: 1554-1556 (1995)
↑ Averdung, J.; Luftmann, H.; Schlachter, I.; Mattay, J. (1995). "Aza-dihydro[60]fullerene in the gas phase. A mass-spectrometric and quantumchemical study". Tetrahedron 51 (25): 6977. doi : 10.1016/0040-4020(95)00361-B
↑ Lamparth, I.; Nuber, B.; Schick, G.; Skiebe, A.; Grösser, T.; Hirsch, A. (1995). "C59N+ and C69N+: Isoelectronic Heteroanalogues of C60 and C70". Angewandte Chemie International Edition in English 34 (20): 2257. doi : 10.1002/anie.199522571
↑ Manaa, Riad; D. W. Sprehn; H. A. Ichord (2002). "Prediction of Extended Aromaticity for a Novel C48N12 Aza-Fullerene Structure". Journal of the American Chemical Society. 124 (47): 13990. doi:10.1021/ja0281885. PMID 12440886.

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[1] Kroto, H.W.; et al. (1985). "C60: Buckminsterfullerene". Nature 318 (6042): 162–163. Bibcode : 1985Natur.318..162K. doi : 10.1038/318162a0

[2] D.J. Harris, Discovery of Nitroballs: Research in Fullerene Chemistry, 1993 California State Science Fair, http://cssf.usc.edu/History/1993/S05.html

[3] Hummelen et al, Isolation of the Heterofullerene C59N as Its Dimer (C59N)2, Science 269: 1554-1556 (1995)

[4] Averdung, J.; Luftmann, H.; Schlachter, I.; Mattay, J. (1995). "Aza-dihydro[60]fullerene in the gas phase. A mass-spectrometric and quantumchemical study". Tetrahedron 51 (25): 6977. doi : 10.1016/0040-4020(95)00361-B

[5] Lamparth, I.; Nuber, B.; Schick, G.; Skiebe, A.; Grösser, T.; Hirsch, A. (1995). "C59N+ and C69N+: Isoelectronic Heteroanalogues of C60 and C70". Angewandte Chemie International Edition in English 34 (20): 2257. doi : 10.1002/anie.199522571

[6] Manaa, Riad; D. W. Sprehn; H. A. Ichord (2002). "Prediction of Extended Aromaticity for a Novel C48N12 Aza-Fullerene Structure". Journal of the American Chemical Society. 124 (47): 13990. doi:10.1021/ja0281885. PMID 12440886.