[1][2] More compounds of carbon exist than any other chemical element except for hydrogen.
One such class of derivatives is inclusion compounds, in which an ion is enclosed by the all-carbon shell of the fullerene.
As with any other ionic compound, this complex ion could in principle pair with a counterion to form a salt.
Carbides are binary compounds of carbon with an element that is less electronegative than it.
Over time, however, scientists learned how to synthesize organic compounds in the lab.
By definition, an organic compound must contain at least one atom of carbon, but this criterion is not generally regarded as sufficient.
Other less known oxides include carbon suboxide (C3O2) and mellitic anhydride (C12O9).
[5] There are also numerous unstable or elusive oxides, such as dicarbon monoxide (C2O), oxalic anhydride (C2O4), and carbon trioxide (CO3).
There are several oxocarbon anions, negative ions that consist solely of oxygen and carbon.
Other more exotic carbon–oxygen anions exist, such as acetylenedicarboxylate (O2C–C≡C–CO22−), mellitate (C12O96−), squarate (C4O42−), and rhodizonate (C6O62−).
Important compound classes are thiocarbonates, thiocarbamates, dithiocarbamates and trithiocarbonates.
Whether it was placed there deliberately or not, some traces of carbon is also found in these common metals and their alloys: aluminum, chromium, magnesium, molybdenum, niobium, thorium, titanium, tungsten, uranium, vanadium, zinc, and zirconium.