Search results
Results from the WOW.Com Content Network
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.
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 .
Fullerenes had been predicted for some time, but only after their accidental synthesis in 1985 were they detected in nature [3] [4] and outer space. [5] [6] The discovery of fullerenes greatly expanded the number of known allotropes of carbon, which had previously been limited to graphite, diamond, and amorphous carbon such as soot and charcoal.
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.
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 ...
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 ...
Tulsi Gabbard, Donald Trump’s pick to lead the intelligence community, was briefly placed on a Transportation Security Administration list that prompts additional security screening before ...
An extract of its leaves is used as a food dye, and imparts a magenta tone to some Vietnamese foods, particularly in a taro-filled cake called bánh da lợn and glutinous rice dishes such as xôi lá cẩm, a sweet dessert.