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.
Buckyball; Fullerene-C60; fullerene
3D model (JSmol)
|Molar mass||720.660 g·mol−1|
|Appearance||Dark needle-like crystals|
|Melting point||≈600 ºC (subl.)|
|insoluble in water|
|Vapor pressure||0.4-0.5 Pa (T ≈ 800 K); 14 Pa (T ≈ 900 K) |
|Face-centered cubic, cF1924|
|Fm3m, No. 225|
a = 1.4154 nm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
It was first generated in 1984 by Eric Rohlfing, Donald Cox and Andrew Kaldor using a laser to vaporize carbon in a supersonic helium beam. In 1985 their work was repeated by Harold Kroto, James R. Heath, Sean O'Brien, Robert Curl, and Richard Smalley at Rice University, who recognized the structure of C60 as buckminsterfullerine. Kroto, Curl and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of buckminsterfullerene and the related class of molecules, the fullerenes.
The discoverers of the allotrope named the newfound molecule after Buckminster Fuller, who designed many geodesic dome structures that look similar to C60. This is slightly misleading, however, as Fuller's geodesic domes are constructed from triangles and not hexagons or pentagons. A common, shortened name for buckminsterfullerene is "buckyballs".
Theoretical predictions of buckyball molecules appeared in the late 1960s and early 1970s, but these reports went largely unnoticed. In the early 1970s, the chemistry of unsaturated carbon configurations was studied by a group at the University of Sussex, led by Harry Kroto and David Walton. In the 1980s, Smalley and Curl at Rice University developed experimental technique to generate these substances. They used laser vaporization of a suitable target to produce clusters of atoms. Kroto realized that by using a graphite target, a range of carbon clusters could be studied.
Concurrent but unconnected to the Kroto-Smalley work, astrophysicists were working with spectroscopists to study infrared emissions from giant red carbon stars. Smalley and team were able to use a laser vaporization technique to create carbon clusters which could potentially emit infrared at the same wavelength as had been emitted by the red carbon star. Hence, the inspiration came to Smalley and team to use the laser technique on graphite to generate fullerenes.
C60 was discovered in 1985 by Robert Curl, Harold Kroto, and Richard Smalley. Using laser evaporation of graphite they found Cn clusters (where n>20 and even) of which the most common were C60 and C70. A solid rotating graphite disk was used as the surface from which carbon was vaporized using a laser beam creating hot plasma that was then passed through a stream of high-density helium gas. The carbon species were subsequently cooled and ionized resulting in the formation of clusters. Clusters ranged in molecular masses, but Kroto and Smalley found predominance in a C60 cluster that could be enhanced further by allowing the plasma react longer. They also discovered that the C60 molecule formed a cage-like structure, a regular truncated icosahedron.
The experimental evidence, a strong peak at 720 atomic mass units, indicated that a carbon molecule with 60 carbon atoms was forming, but provided no structural information. The research group concluded after reactivity experiments, that the most likely structure was a spheroidal molecule. The idea was quickly rationalized as the basis of an icosahedral symmetry closed cage structure. Kroto mentioned geodesic dome structures of the noted futurist and inventor Buckminster Fuller as influences in the naming of this particular substance as buckminsterfullerene.
In 1989 physicists Wolfgang Krätschmer, Konstantinos Fostiropoulos, and Donald R. Huffman observed unusual optical absorptions in thin films of carbon dust (soot). The soot had been generated by an arc-process between two graphite electrodes in a helium atmosphere where the electrode material evaporates and condenses forming soot in the quenching atmosphere. Among other features, the IR spectra of the soot showed four discrete bands in close agreement to those proposed for C60.
Another paper on the characterization and verification of the molecular structure followed on in the same year (1990) from their thin film experiments, and detailed also the extraction of an evaporable as well as benzene soluble material from the arc-generated soot. This extract had TEM and X-ray crystal analysis consistent with arrays of spherical C60 molecules, approximately 1.0 nm in van der Waals diameter as well as the expected molecular mass of 720 u for C60 (and 840 u for C70) in their mass spectra. The method was simple and efficient to prepare the material in gram amounts per day (1990) which has boosted the fullerene research and is even today applied for the commercial production of fullerenes.
The discovery of practical routes to C60 led to the exploration of a new field of chemistry involving the study of fullerenes.
Soot is produced by laser ablation of graphite or pyrolysis of aromatic hydrocarbons. Fullerenes are extracted from the soot with organic solvents using a Soxhlet extractor. This step yields a solution containing up to 75% of C60, as well as other fullerenes. These fractions are separated using chromatography. Generally, the fullerenes are dissolved in a hydrocarbon or halogenated hydrocarbon and separated using alumina columns.
Buckminsterfullerene is a truncated icosahedron with 60 vertices and 32 faces (20 hexagons and 12 pentagons where no pentagons share a vertex) with a carbon atom at the vertices of each polygon and a bond along each polygon edge. The van der Waals diameter of a C
60 molecule is about 1.01 nanometers (nm). The nucleus to nucleus diameter of a C
60 molecule is about 0.71 nm. The C
60 molecule has two bond lengths. The 6:6 ring bonds (between two hexagons) can be considered "double bonds" and are shorter than the 6:5 bonds (between a hexagon and a pentagon). Its average bond length is 0.14 nm. Each carbon atom in the structure is bonded covalently with 3 others.
The compound is stable, withstanding high temperatures and high pressures. The exposed surface of the structure can selectively react with other species while maintaining the spherical geometry. Beam experiments conducted between 1985 and 1990 provided more evidence for the stability of C60 while supporting the closed-cage structural theory and predicting some of the bulk properties such a molecule would have. Around this time, intense theoretical group theory activity also predicted that C60 should have only four IR-active vibrational bands, on account of its icosahedral symmetry.
60 undergoes six reversible, one-electron reductions to C6−
60, but oxidation is irreversible. The first reduction needs ≈1.0 V (Fc/Fc+
), showing that C60 is a moderately effective electron acceptor. C
60 tends to avoid having double bonds in the pentagonal rings, which makes electron delocalization poor, and results in C
60 not being "superaromatic". C60 behaves very much like an electron deficient alkene and readily reacts with electron rich species.
A carbon atom in the C
60 molecule can be substituted by a nitrogen or boron atom yielding a C
59N or C59B respectively.
|water||1.3 × 10−11|
Fullerenes are sparingly soluble in aromatic solvents such as toluene and carbon disulfide, but insoluble in water. Solutions of pure C60 have a deep purple color which leaves a brown residue upon evaporation. The reason for this color change is the relatively narrow energy width of the band of molecular levels responsible for green light absorption by individual C60 molecules. Thus individual molecules transmit some blue and red light resulting in a purple color. Upon drying, intermolecular interaction results in the overlap and broadening of the energy bands, thereby eliminating the blue light transmittance and causing the purple to brown color change.
60 crystallises with some solvents in the lattice ("solvates"). For example, crystallization of C60 in benzene solution yields triclinic crystals with the formula C60·4C6H6. Like other solvates, this one readily releases benzene to give the usual fcc C60. Millimeter-sized crystals of C60 and C
70 can be grown from solution both for solvates and for pure fullerenes.
In solid buckminsterfullerene, the C60 molecules adopt the fcc (face-centered cubic) motif. They start rotating at about −20 °C. This change is associated with a first-order phase transition to a fcc structure and a small, yet abrupt increase in the lattice constant from 1.411 to 1.4154 nm.
60 solid is as soft as graphite, but when compressed to less than 70% of its volume it transforms into a superhard form of diamond (see aggregated diamond nanorod). C
60 films and solution have strong non-linear optical properties; in particular, their optical absorption increases with light intensity (saturable absorption).
60 forms a brownish solid with an optical absorption threshold at ≈1.6 eV. It is an n-type semiconductor with a low activation energy of 0.1–0.3 eV; this conductivity is attributed to intrinsic or oxygen-related defects. Fcc C60 contains voids at its octahedral and tetrahedral sites which are sufficiently large (0.6 and 0.2 nm respectively) to accommodate impurity atoms. When alkali metals are doped into these voids, C60 converts from a semiconductor into a conductor or even superconductor.
C60 exhibits a small degree of aromatic character, but it still reflects localized double and single C–C bond characters. Therefore, C60 can undergo addition with hydrogen to give polyhydrofullerenes. C60 also undergoes Birch reduction. For example, C60 reacts with lithium in liquid ammonia, followed by tert-butanol to give a mixture of polyhydrofullerenes such as C60H18, C60H32, C60H36, with C60H32 being the dominating product. This mixture of polyhydrofullerenes can be re-oxidized by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone to give C60 again.
Selective hydrogenation method exists. Reaction of C60 with 9,9′,10,10′-dihydroanthracene under the same conditions, depending on the time of reaction, gives C60H32 and C60H18 respectively and selectively.
C60 can be hydrogenated, suggesting that a modified buckminsterfullerene called organometallic buckyballs (OBBs) could become a vehicle for "high density, room temperature, ambient pressure storage of hydrogen". These OBBs are created by binding atoms of a transition metal (TM) to C60 or C48B12 and then binding many hydrogen atoms to this TM atom, dispersing them evenly throughout the inside of the organometallic buckyball. The study found that the theoretical amount of H2 that can be retrieved from the OBB at ambient pressure approaches 9 wt %, a mass fraction that has been designated as optimal for hydrogen fuel by the U.S. Department of Energy.
Fluorine atoms are small enough for a 1,2-addition, while Cl2 and Br2 add to remote C atoms due to steric factors. For example, in C60Br8 and C60Br24, the Br atoms are in 1,3- or 1,4-positions with respect to each other.
Under various conditions a vast number of halogenated derivatives of C60 can be produced, some with extraordinary selectivity on one or two isomers over the other possible ones.
Addition of fluorine and chlorine usually results in a flattening of the C60 framework into a drum-shaped molecule.
Solutions of C60 can be oxygenated to the epoxide C60O. Ozonation of C60 in 1,2-xylene at 257K gives an intermediate ozonide C60O3, which can be decomposed into 2 forms of C60O. Decomposition of C60O3 at 296 K gives the epoxide, but photolysis gives a product in which the O atom bridges a 5,6-edige.
The Diels–Alder reaction is commonly employed to functionalize C60. Reaction of C60 with appropriate substituted diene gives the corresponding adduct.
The Diels–Alder reaction between C60 and 3,6-diaryl-1,2,4,5-tetrazines affords C62. The C62 has the structure in which a four-membered ring is surrounded by four six-membered rings.
The C60 molecules can also be coupled through a [2+2] cycloaddition, giving the dumbbell-shaped compound C120. The coupling is achieved by high-speed vibrating milling of C60 with a catalytic amount of KCN. The reaction is reversible as C120 dissociates back to two C60 molecules when heated at 450 K (177 °C; 350 °F). Under high pressure and temperature, repeated [2+2] cycloaddition between C60 results in a polymerized fullerene chains and networks. These polymers remain stable at ambient pressure and temperature once formed, and have remarkably interesting electronic and magnetic properties, such as being ferromagnetic above room temperature.
Reactions of C60 with free radicals readily occur. When C60 is mixed with a disulfide RSSR, the radical C60SR• forms spontaneously upon irradiation of the mixture.
Cyclopropanation (the Bingel reaction) is another common method for functionalizing C60. Cyclopropanation of C60 mostly occurs at the junction of 2 hexagons due to steric factors.
The first cyclopropanation was carried out by treating the β-bromomalonate with C60 in the presence of a base. Cyclopropanation also occur readily with diazomethanes. For example, diphenyldiazomethane reacts readily with C60 to give the compound C61Ph2. Phenyl-C61-butyric acid methyl ester derivative prepared through cyclopropanation has been studied for use in organic solar cells.
The LUMO in C60 is triply degenerate, with the HOMO–LUMO separation relatively small. This small gap suggests that reduction of C60 should occur at mild potentials leading to fulleride anions, [C60]n− (n = 1–6). The midpoint potentials of 1-electron reduction of buckminsterfullerene and its anions is given in the table below:
|Reduction potential of C60 at 213 K|
|C60 + e− ⇌ C−
60 + e− ⇌ C2−
60 + e− ⇌ C3−
60 + e− ⇌ C4−
60 + e− ⇌ C5−
60 + e− ⇌ C6−
This salt exhibits ferromagnetism at 16 K.
C60 oxidizes with difficulty. Three reversible oxidation processes have been observed by using cyclic voltammetry with ultra-dry methylene chloride and a supporting electrolyte with extremely high oxidation resistance and low nucleophilicity, such as [nBu4N] [AsF6].
|Reduction potentials of C60 oxidation at low temperatures|
|C60 ⇌ C+
60 ⇌ C2+
60 ⇌ C3+
Which the [C60]2+ ion is very unstable, and the third process can be studied only at low temperatures.
The redox potentials of C60 can be modified supramolecularly. A dibenzo-18-crown-6 derivative of C60 has been made, featuring a voltage sensor device, with the reversible binding of K+ ion causing an anodic shift of 90mV of the first C60 reduction.
C60 forms complexes akin to the more common alkenes. Complexes have been reported molybdenum, tungsten, platinum, palladium, iridium, and titanium. The pentacarbonyl species are produced by photochemical reactions.
In the case of platinum complex, the labile ethylene ligand is the leaving group in a thermal reaction:
Titanocene complexes have also been reported:
One such iridium complex, [Ir(η2-C60)(CO)Cl(Ph2CH2C6H4OCH2Ph)2] has been prepared where the metal center projects two electron-rich 'arms' that embrace the C60 guest.
Metal atoms or certain small molecules such as H2 and noble gas can be encapsulated inside the C60 cage. These endohedral fullerenes are usually synthesized by doping in the metal atoms in an arc reactor or by laser evaporation. These methods gives low yields of endohedral fullerenes, and a better method involves the opening of the cage, packing in the atoms or molecules, and closing the opening using certain organic reactions. This method, however, is still immature and only a few species have been synthesized this way.
Endohedral fullerenes show distinct and intriguing chemical properties that can be completely different from the encapsulated atom or molecule, as well as the fullerene itself. The encapsulated atoms have been shown to perform circular motions inside the C60 cage, and its motion has been followed by using NMR spectroscopy.
In the medical field, elements such as helium (that can be detected in minute quantities) can be used as chemical tracers in impregnated buckyballs.
The optical absorption properties of C60 match solar spectrum in a way that suggests that C60-based films could be useful for photovoltaic applications. Because of its high electronic affinity  it is one of the most common electron acceptors used in donor/acceptor based solar cells. Conversion efficiencies up to 5.7% have been reported in C60–polymer cells.
Solutions of C60 dissolved in olive oil are nontoxic to rodents.
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
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.Buckyball (disambiguation)
A buckyball or buckminsterfullerene is a molecule resembling a soccer ball composed of 60 carbon atoms.
Buckyball may alo refer to:
Truncated icosahedron, the geometric structure of the C60 molecule
A brand of neodymium magnet toysC70 fullerene
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.
It was first intentionally prepared in 1985 by Harold Kroto, James R. Heath, Sean O'Brien, Robert Curl and Richard Smalley at Rice University. Kroto, Curl and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of cage-like fullerenes. The name is a homage to Buckminster Fuller, whose geodesic domes these molecules resemble.Corannulene
Corannulene is a polycyclic aromatic hydrocarbon with chemical formula C20H10. The molecule consists of a cyclopentane ring fused with 5 benzene rings, so another name for it is circulene. It is of scientific interest because it is a geodesic polyarene and can be considered a fragment of buckminsterfullerene. Due to this connection and also its bowl shape, corannulene is also known as a buckybowl. Corannulene exhibits a bowl-to-bowl inversion with an inversion barrier of 10.2 kcal/mol (42.7 kJ/mol) at −64 °C.Donald Huffman
Donald R. Huffman (born 1935) is a Professor Emeritus of Physics at the University of Arizona. With Wolfgang Krätschmer, he developed a technique in 1990 for the simple production of large quantities of C60, or Buckminsterfullerene. Previously, in 1982~1983, he and Krätschmer had found, in a UV spectrum, the first signal of C60 ever observed.Dr. Huffman was featured prominently in the PBS Nova documentary, originally aired in 1995, "Race to Catch a Buckyball".Drexler–Smalley debate on molecular nanotechnology
The Drexler–Smalley debate on molecular nanotechnology was a public dispute between K. Eric Drexler, the originator of the conceptual basis of molecular nanotechnology, and Richard Smalley, a recipient of the 1996 Nobel prize in Chemistry for the discovery of the nanomaterial buckminsterfullerene. The dispute was about the feasibility of constructing molecular assemblers, which are molecular machines which could robotically assemble molecular materials and devices by manipulating individual atoms or molecules. The concept of molecular assemblers was central to Drexler's conception of molecular nanotechnology, but Smalley argued that fundamental physical principles would prevent them from ever being possible. The two also traded accusations that the other's conception of nanotechnology was harmful to public perception of the field and threatened continued public support for nanotechnology research.
The debate was carried out from 2001 to 2003 through a series of published articles and open letters. It began with a 2001 article by Smalley in Scientific American, which was followed by a rebuttal published by Drexler and coworkers later that year, and two open letters by Drexler in early 2003. The debate was concluded in late 2003 in a "Point–Counterpoint" feature in Chemical & Engineering News in which both parties participated.
The debate has been often cited in the history of nanotechnology due to the fame of its participants and its commentary on both the technical and social aspects of nanotechnology. It has also been widely criticized for its adversarial tone, with Drexler accusing Smalley of publicly misrepresenting his work, and Smalley accusing Drexler of failing to understand basic science, causing commentators to go so far as to characterize the tone of the debate as similar to "a pissing match" and "reminiscent of [a] Saturday Night Live sketch".Fullerene
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 (or sometimes heptagonal) rings.The first fullerene molecule to be discovered, and the family's namesake, buckminsterfullerene (C60), was manufactured in 1985 by Richard Smalley, Robert Curl, James Heath, Sean O'Brien, and Harold Kroto at Rice University. The name was an homage to Buckminster Fuller, whose geodesic domes it resembles. The structure was also identified some five years earlier by Sumio Iijima, from an electron microscope image, where it formed the core of a "bucky onion". Fullerenes have since been found to occur in nature. More recently, fullerenes have been detected in outer space. According to astronomer Letizia Stanghellini, "It’s possible that buckyballs from outer space provided seeds for life on Earth."The discovery of fullerenes greatly expanded the number of known carbon allotropes, which had previously been limited to graphite, graphene, diamond, and amorphous carbon such as soot and charcoal. Buckyballs and buckytubes have been the subject of intense research, both for their chemistry and for their technological applications, especially in materials science, electronics, and nanotechnology.Fulleride
Fullerides are chemical compounds containing fullerene anions. Common fullerides are derivatives of the most common fullerenes, i.e. C60 and C70. The scope of the area is large because multiple charges are possible, i.e., [C60]n− (n = 1, 2...6), and all fullerenes can be converted to fullerides. The suffix "-ide" implies their negatively charged nature.
Fullerides can be isolated as derivatives with a wide range of cations. Most heavily studied derivatives are those with alkali metals, but fullerides have been prepared with organic cations. Fullerides are typically dark colored solids that generally dissolve in polar organic solvents.Harry Kroto
Sir Harold Walter Kroto (born Harold Walter Krotoschiner; 7 October 1939 – 30 April 2016), 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.
Kroto held many positions in academia throughout his life, most notably the Francis Eppes Professor of Chemistry at the Florida State University, which he joined in 2004. Prior to this, he spent a large part of his career at the University of Sussex, where he held an emeritus professorship.Kroto promoted science education and was a critic of religious faith.Homonuclear molecule
Homonuclear molecules, or homonuclear species, are molecules composed of only one type of element. Homonuclear molecules may consist of various numbers of atoms, depending on the element's properties. Some elements form molecules of more than one size. Noble gases rarely form bonds, so they only have one atom. The most familiar homonuclear molecules are diatomic, meaning they consist of two atoms, though not all diatomic molecules are homonuclear. Homonuclear diatomic molecules include hydrogen (H2), oxygen (O2), nitrogen (N2) and all of the halogens. Ozone (O3) is a common triatomic homonuclear molecule. Homonuclear tetratomic molecules include arsenic (As4) and phosphorus (P4).
Allotropes are different chemical forms of the same element (not containing any other element). In that sense, allotropes are all homonuclear. Many elements have multiple allotropic forms. In addition to the most common form of gaseous oxygen, O2, and ozone, there are other allotropes of oxygen. Sulfur forms several allotropes containing different numbers of sulfur atoms, including diatomic, triatomic, hexatomic and octatomic (S2, S3, S6, S8) forms, though the first three are rare. The element carbon is known to have a number of homonuclear molecules, the best known being buckminsterfullerene or "buckyball".Osmium tetroxide
Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO4. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of interesting properties, one being that the solid is volatile. The compound is colourless, but most samples appear yellow. This is most likely due to the presence of the impurity OsO2, which is yellow-brown in colour.Richard Smalley
Richard Errett Smalley (June 6, 1943 – October 28, 2005) 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.Robert Curl
Robert Floyd Curl Jr. (born August 23, 1933) 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 (also of Rice University) and Harold Kroto of the University of Sussex.Sean O'Brien
Sean O'Brien may refer to:
Seán O'Brien (Gaelic footballer), Gaelic footballer with Nemo Rangers
Seán O'Brien (hurler) (1926–?), Irish hurler
Sean O'Brien (Tipperary hurler), Irish sportsperson
Sean O'Brien (ice hockey) (born 1972), American former ice hockey left winger
Sean O'Brien (Ohio politician) (born 1969), Democratic member of the Ohio Senate
Seán O'Brien (rugby player, born 1987), Irish rugby union footballer of the 2000s and 2010s
Seán O'Brien (rugby player born 1994), Irish rugby union footballer of the 2010s
Sean O'Brien (windsurfer) (born 1984), Australian windsurfer
Sean O'Brien (writer) (born 1952), British writer
Sean O'Brien (musician), bassist and original member of Boston rock band Come
Sean C. O'Brien, co-discoverer of buckminsterfullereneSpherical aromaticity
In organic chemistry, spherical aromaticity is formally used to describe an unusually stable nature of some spherical compounds such as fullerenes, polyhedral boranes.
In 2000, Andreas Hirsch and coworkers in Erlangen, Germany, formulated a rule to determine when a fullerene would be aromatic. They found that if there were 2(n+1)2 π-electrons, then the fullerene would display aromatic properties. This follows from the fact that an aromatic fullerene must have full icosahedral (or other appropriate) symmetry, so the molecular orbitals must be entirely filled. This is possible only if there are exactly 2(n+1)2 electrons, where n is a nonnegative integer. In particular, for example, buckminsterfullerene, with 60 π-electrons, is non-aromatic, since 60/2 = 30, which is not a perfect square.In 2011, Jordi Poater and Miquel Solà, expanded the rule to determine when a fullerene species would be aromatic. They found that if there were 2n2+2n+1 π-electrons, then the fullerene would display aromatic properties. This follows from the fact that a spherical species having a same-spin half-filled last energy level with the whole inner levels being fully filled is also aromatic. It is similar to Baird's rule.Sumanene
Sumanene is a polycyclic aromatic hydrocarbon and of scientific interest because the molecule can be considered a fragment of buckminsterfullerene. Suman means "sunflower" in both Hindi and Sanskrit. The core of the arene is a benzene ring and the periphery consists of alternating benzene rings (3) and cyclopentadiene rings (3). Unlike fullerene, sumanene has benzyl positions which are available for organic reactions.Transition metal fullerene complex
A transition metal fullerene complex is a coordination complex wherein fullerene serves as a ligand. Fullerenes are typically spheroidal carbon compounds, the most prevalent being buckminsterfullerene, C60.One year after it was prepared in milligram quantities in 1990, C60 was shown to function as a ligand in the complex [Ph3P]2Pt(η2-C60).Since this report, a variety of transition metals and binding modes were demonstrated. Most transition metal fullerene complex are derived from C60, although other fullerenes also coordinate to metals as seen with C70Rh(H)(CO)(PPh3)2.Wiess School of Natural Sciences
The Wiess School of Natural Sciences is an academic school at Rice University in Houston, Texas. It comprises the departments of BioSciences (a merging of Biochemistry and Cell Biology and Ecology and Evolutionary Biology); Chemistry; Earth, Environment and Planetary Sciences; Kinesiology; Mathematics; and Physics and Astronomy. Rice is well known for its groundbreaking research in nanotechnology. As well as undergraduate in instruction, the school also supports a professional science master's program. One of Rice's greatest minds and pioneers of the field was Richard Smalley, the Norman Hackerman Professor of Chemistry and Professor of Physics and Astronomy. Smalley received the Nobel Prize (along with chemist Robert Curl) in 1996 for the discovery buckminsterfullerene, an allotrope of carbon commonly referred to as "buckyballs".