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S3-
The molecule, known as trisulfur, sulfur trimer, thiozone, or triatomic sulfur, is a cherry-red allotrope of sulfur. It comprises about 10% of vaporised sulfur at and . It has been observed at cryogenic temperatures as a solid. Under ordinary conditions it converts to cyclooctasulfur. :8 S3 ā 3 S8 Structure and bonding In terms of structure and bonding and ozone () are similar. Both adopt bent structures and are diamagnetic. Although represented with S=S double bonds, the bonding situation is more complex. The SāS distances are equivalent and are , and with an angle at the central atom of . However, cyclic , where the sulfur atoms are arranged in an equilateral triangle with three single bonds (similar to cyclic ozone and cyclopropane), is calculated to be lower in energy than the bent structure experimentally observed. The name thiozone was invented by Hugo Erdmann in 1908 who hypothesized that comprises a large proportion of liquid sulfur. However its existence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultramarine
Ultramarine is a deep blue color pigment which was originally made by grinding lapis lazuli into a powder. The name comes from the Latin ''ultramarinus'', literally 'beyond the sea', because the pigment was imported into Europe from mines in Afghanistan by Italian traders during the 14th and 15th centuries. Ultramarine was the finest and most expensive blue used by Renaissance painters. It was often used for the robes of the Virgin Mary and symbolized holiness and humility. It remained an extremely expensive pigment until a synthetic ultramarine was invented in 1826. Structure The pigment consists primarily of a zeolite-based mineral containing small amounts of polysulfides. It occurs in nature as a proximate component of lapis lazuli containing a blue cubic mineral called lazurite. In the Colour Index International, the pigment of ultramarine is identified as P. Blue 29 77007. The major component of lazurite is a complex sulfur-containing sodium-silicate (Na8ā10Al6Si6O24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |