# Should carbon tetrachloride really be considered an organic compound?

Wikipedia says:

Carbon tetrachloride […] is an organic compound with the chemical formula $\ce{CCl4}$.

From an organic point of view, carbon tetrachloride can be called the tetrachloro derivative of methane and is described in many organic textbook along with $\ce{CH3Cl}$, $\ce{CH2Cl2}$ and $\ce{CHCl3}$.

From an inorganic point of view, carbon tetrachloride can be considered chloride of a group 14 element (along with $\ce{SiCl4}$, $\ce{GeCl4}$).

Shouldn’t carbon tetrachloride be considered an inorganic compound? It neither contains any $\ce{C-H}$ bond nor is it found in any living organism.

Tetrachloromethane is its organic name. But it is generally not called by this name. Carbon tetrachloride is its better name and inorganic compounds are named like that.

• The distinction organic/inorganic is (often) not a very useful one, except to put the word on books, lectures and institute names. ;) All (in)organic molecular chemistry people speak basically the same language. Chemistry of inorganic solids and ionic melts is something much different, for example. – Karl Apr 18 '16 at 15:45
• As Karl said, does it really matter? – bon Apr 18 '16 at 16:03
• – Ilmari Karonen Apr 18 '16 at 21:24

There are a number of questions here on Stack Exchange discussing the distinction between organic and inorganic compounds, such as:

The distinction between organic and inorganic chemistry is one that is upheld mainly because of traditional reasons. It is also upheld because some more specialised fields are often well included into one of the two traditional definitions: solid state chemistry is usually inorganic while natural product synthesis is almost entirely organic chemistry by all applicable definitions (save the very old historical ones).

But remember that there are a number of fields that straddle the boundary. Coordination chemistry often involves organic and inorganic ligands around an inorganic metal centre. It depends on the research being performed whether the group wishes to be considered organic or inorganic. See for example the groups of Professor Klüfers and Professor Knochel at the LMU Munich: The former classifies himself as an inorganic chemist and investigates carbohydrate-metal complexes among other things; the latter classifies himself as an organic chemist and investigates organometallic reagents and reactions.

So in a way, the organic/inorganic distinction compares well to the border between Europe and Asia. Everyone will agree that France is in Europe and China is in Asia but what about Georgia and Turkey?

Note that your dualism is short-handed. $\ce{SiHCl3}$, trichlorosilane or silicochloroform is produced in an industrial scale and trichlorogermane $\ce{GeHCl3}$ is also known. On the silicon side of things, apart from tri- and tetrachlorosilane the di- and monochlorosilanes $\ce{SiH2Cl2}$ and $\ce{SiH3Cl}$ are known just like their carbon counterparts. And of course, silane $\ce{SiH4}$ is known, too. (I am not sure exactly how much is known about the corresponding germanium compounds. The English Wikipedia didn’t have entries for them but didn’t contain trichlorogermane either, which was only present in German and Russian.)

So beware when drawing analogies. They could go into a different direction that you may think.

Speaking of surprising facts: Did you know that chloromethane is the most-produced secondary metabolite by mass? So let’s add chlorosilane into the organic realm by analogy!

Finally, as an aside note: I actually use tetrachloromethane much more than I would carbon tetrachloride; that goes for both languages in which I do chemistry.

• Its been a while that you answered some question here.... – Nilay Ghosh Apr 19 '16 at 7:49
• @NilayGhosh That’s true. I needed to take a break to concentrate on practical work ;) – Jan Apr 19 '16 at 11:52

Simple carbon compounds such as the tetrachloride blur the boundary between organic and inorganic. You should know that presence in natural systems is not an indicator of a compound being organic; many organic compounds are completely artificial, though they may be derived from natural feedstocks.

There is no strict criteria for organicity (is there a better word?). Consider perfluorinated carboxylic acids, they have no C-H bonds but are considered organic.

• Or HCN, definitely inorganic, right? But what about cyanogen NC-CN? Ethine is organic, but acetlyides? – Karl Apr 18 '16 at 15:55
• Simple carbon ions are considered inorganic. – gsurfer04 Apr 18 '16 at 20:59
• I would assert HCN is definitely an organic compound. – Lighthart Apr 19 '16 at 6:15
• @Karl I agree with Lighthart's comment because HCN is found in fruits like apples, cherries, almonds etc. and also in mammals. See wikipedia page of HCN(occurence). – Nilay Ghosh Apr 19 '16 at 7:53
• That's debatable: HCN is also a pseudohalogenic acid, cyanogen the corresponding pseudohalogen. – Karl Apr 19 '16 at 8:03