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Fullerene or C 60 is soccer-ball-shaped or I h with 12 pentagons and 20 hexagons. According to Euler's theorem these 12 pentagons are required for closure of the carbon network consisting of n hexagons and C 60 is the first stable fullerene because it is the smallest possible to obey this rule.
The older, "bottom-up" theory proposes that they are built atom-by-atom. The alternative "top-down" approach claims that fullerenes form when much larger structures break into constituent parts. [74] In 2013 researchers discovered that asymmetrical fullerenes formed from larger structures settle into stable fullerenes.
In organic chemistry, spherical aromaticity is formally used to describe an unusually stable nature of some spherical compounds such as fullerenes and polyhedral boranes.. In 2000, Andreas Hirsch and coworkers in Erlangen, Germany, formulated a rule to determine when a spherical compound would be aromatic.
Besides unfilled fullerenes, endohedral metallofullerenes develop with different cage sizes like La@C 60 or La@C 82 and as different isomer cages. Aside from the dominant presence of mono-metal cages, numerous di-metal endohedral complexes and the tri-metal carbide fullerenes like Sc 3 C 2 @C 80 were also isolated. In 1999 a discovery drew ...
They are called intrinsic polymeric fullerenes, or more often all C 60 polymers. Fullerene can be part of a polymer chain in many different ways. Fullerene-containing polymers are divided into following structural categories: Intrinsic polymeric fullerene (homopolymer), Main-chain polymers, Side-chain polymers, Star polymers, Crosslinked polymers,
Fullerenes are typically spheroidal carbon compounds, the most prevalent being buckminsterfullerene, C 60. [2] One year after it was prepared in milligram quantities in 1990, [3] C 60 was shown to function as a ligand in the complex [Ph 3 P] 2 Pt(η 2-C 60). [4] Since this report, a variety of transition metals and binding modes were demonstrated.
Astronomers mistook a car SpaceX blasted into space years ago as an asteroid. The brief mix-up highlights the sometimes difficult pursuit of tracking deep-space objects.
Below there are lists the nearest stars separated by spectral type. The scope of the list is still restricted to the main sequence spectral types: M , K , F , G , A , B and O . It may be later expanded to other types, such as S , D or C .