3 ms·

As far as I understand, the non-nitrogen atoms in the reaction are provided by benzene. Fun fact: benzene is so important in chemistry that it has two unicode

• thaumasiotes 6y ago
  Well, unicode doesn't have much to do with chemistry, or with importance. Those two symbols both long predate unicode (as you'd expect given the nature of unicode). The reason for the second symbol is that the positioning of the double bonds within the ring is underdetermined (and indeed, doesn't really exist) -- they are in a state of indeterminate flux much like the bonds in a molecule of ozone. The circle explicitly acknowledges that we can't really identify particular bonds as being the double bonds.
  • EE84M3i 6y ago
    >Those two symbols both long predate unicode (as you'd expect given the nature of unicode). Yes, but notably they are not included in Unicode for compatibility with legacy character sets.
    • thaumasiotes 6y ago
      Are they included in Unicode for any reason? They're not textual and don't make any sense (they are actually ill-formed[1]) as independent glyphs. [1] OK, they're not ill-formed if you really want to insert a miniature icon of a free benzene molecule into running text, but in chemistry you're mostly talking about benzene rings as a structural element in larger molecules, not molecular benzene.