10
$\begingroup$

This question may seem vague at a first glance, and even lead to the thought: "come on, just go Google it!"

But it's a real question because it does not make enough sense to me (even after Googling it, a lot).

I was just presented to the words, but not to their definition.

Like: "Hey, now we will speak about organic nomenclature".

At some point, books and videos start talking about inorganic and organic as if it was a common sense thing.

A frequent rule I found while trying to understand the difference:

  • Organic: has carbon
  • Inorganic: does not have carbon

But then, some inorganic compounds do have carbon too, and there may even be some compounds that some call organic, and others call inorganic, like $CO_2$.

As I have felt it, in my learnings so far, it's like inorganic chemistry is the default chemistry and organic chemistry goes a step beyond.

But I don't quite grasp the difference.

What is the real semantics behind the word "organic"?

For example, we humans are made of loads of water, and that's a pretty organic thing to me. But then, water is inorganic.

Diamonds are the carbon top of the cake, and do not transmit the idea of being an "organic" thing.

Another very confusing thing are polymers, chanins of loads of carbons with other elements, in many shapes and textures. To me, a piece of "plastic" is not a very organic thing, but indeed, they are!

That brings the semantics into an even more confusing level.

And of course, there must be historical reasons for those chosen words.

Could someone please point out where this distinction comes from and why it is important?

With all my respect to science and the people who made chemistry a useful thing. This question is not about critics, it's about not knowing the facts, so of course I am the ignorant here.

Related and useful: What is the definition of organic compounds?

$\endgroup$
6
  • 6
    $\begingroup$ Organic chemistry refers to study of compounds that are derived from nature and their derivatives, and was thought to be impossible to create by us. When Woehler did so, still such compounds were still continued to be called 'organic' to continue the 'tradition'. $\endgroup$
    – ba-13
    May 6 '20 at 15:41
  • $\begingroup$ @B.Anshuman That is a very interesting point. Thank you a lot. $\endgroup$ May 6 '20 at 15:44
  • $\begingroup$ For future reference, use \ce{} for writing chemical formulas. Please take a visit tour page, and a page on meta, on how to edit your question (I am too lazy to search for the links). $\endgroup$
    – Zenix
    May 6 '20 at 15:58
  • 1
    $\begingroup$ Related: chemistry.stackexchange.com/questions/102586/… $\endgroup$ May 6 '20 at 16:07
  • 1
    $\begingroup$ It's a standard duplicate target, and here's seems to be one answer too much already chemistry.stackexchange.com/questions/14246/… $\endgroup$
    – Mithoron
    May 7 '20 at 16:20
14
$\begingroup$

IUPAC is the International Union of Pure and Applied Chemistry, they make recommendations on the nomenclature. IUPAC mentions that the difference between organic and inorganic is not distinct. To quote "The boundaries between ‘organic’ and ‘inorganic’ compounds are blurred." in Brief Guide to the Nomenclature of Inorganic Chemistry R. M. Hartshorn, K.-H. Hellwich, A. Yerin.

Since the terminology of organic vs. inorganic is all human classification, it is not a binary system 0 or 1. What we can say now is that traditionally, all organic compounds do contain carbon. It can come from natural sources or purely synthetic. There is no such restriction. Plastic is an organic compound because it contains a lot of carbon chains.

Note that this word organic, as used in chemistry, has nothing to with the buzz word used in marketing of organic food, organic fruits, organically grown stuff. The word organic comes from French organique designating the jugular vein, hence related to organs or living beings.

It is a myth that Wohler started the distinction of organic vs. inorganic. There is a nice French article. The 16-paged paper is titled “Les origines de la chimie organique au-delà du mythe fondateur” (The origins of organic chemistry beyond the founding myth), Comptes Rendus Chimie, 2012, 15, 553–568.

Read the table at the end, and the abstract.

It clearly shows that Berzelius coined the term organic chemistry between 1807-1813.

Use Google Translate or DeepL to translate it.

$\endgroup$
2
  • 2
    $\begingroup$ This is a beautiful precious answer, thanks a lot for it. I will read it again a few times. Link to the paper you mention: researchgate.net/publication/… $\endgroup$ May 6 '20 at 16:05
  • $\begingroup$ Plastic is an interesting edge case. It is, by definition, organic chemistry. But most of its properties are studied as part of inorganic chemistry... And many other polymer type materials sneak their way into the inorganic sphere because we have found they can have inorganic type qualities. OLEDs, graphene, LCDs... The line is not easily drawn these days. (But I'll still get angry if people assume me for a filthy organic chemist!) j/k... $\endgroup$ May 7 '20 at 11:52
7
$\begingroup$

Historically, organic chemistry was the chemistry done by living organism. It was (back in time) supposed to recquire some sort of divine element/intervention to be done, and therefore could not be done artificially (outside of a living organism). Since the discovery of artificial synthesis of urea in 1828 by Friedrich Wöhler, and the many more that followed, the definition of organic chemistry changed a lot.

Today, organic chemistry designate the chemistry of covalent bond. Those are mostly done by carbon and hydrogen atoms, and a few other hetero-atoms mostly oxygen, nitrogen and halogen. The way of reasoning in organic chemistry is to have a carbon skeleton, on which you will put functional group (which often will include hetero-atom). Despite not having carbon atom, you can consider the water molecule as an organic molecule (bonds are covalent). Some organic reaction can produce or consume water molecule, or need to be done in water. Same goes for $NH_3$.

Inorganic chemistry designate the chemistry of ionic and coordination bonds. It mostly focus on metal atoms. For a chemist, a metal atom is an atom that can lose up to 4 electrons (it is different from the physics definition, which defines metal by their macroscopic properties). A simple example of ionic bond is NaCl.

Coordination bond involve metal and organic molecule, therefore do mind that both fields are not exclusive. You can do inorganic chemistry with organic molecule (chelation of metal ions by ethylenediamine for example), or organic chemistry with metals (synthesis of crown ether using the template effect of a metal).

Plastics are organics polymers, salts can be seen as metal polymers (but nobody does). You can create polymers that use both organics molecules and metals, in which case you will do both organic and inorganic chemistry! (keywords for example would be "self-assembly coordination polymers", unfortunately all examples I can find come from publication behind paywall)

Finally, to go back to living organism, we know today that metal ions play a huge part in living organism. Bioinorganic chemistry is the field that study reactions of metal inside living organism. The early anti-cancer drug cis-palladium is the textbook example for this field.

$\endgroup$
3
  • $\begingroup$ Amon, If you could access and read the article Les origines de la chimie organique au-delà du mythe fondateur The origins of organic chemistry beyond the founding myth"sciencedirect.com/science/article/pii/S1631074812000331, you will see that it is a myth that Wohler did a magical urea synthesis and ushered a new era in organic chemistry. It is in French, but machine translation of it is pretty good, that what I read last year for some other pupose. $\endgroup$
    – M. Farooq
    May 6 '20 at 16:47
  • $\begingroup$ This is a very hepful answer too, Amon. And I will keep researching on all the facts that you expressed here. I will keep M. Farooq's as the accepted answer because it actually answers the question, as well as your answer. But I appreciate them both and the real answer is a combination of both. Thanks a lot. $\endgroup$ May 6 '20 at 16:59
  • 1
    $\begingroup$ @M.Farooq Sorry, I was still writing my answer when you post yours. Regarding your comment, of course organic chemistry didn't appear out of thin air and it took time for the "vitalism" to disappear. Synthesis of urea is very often considered to be the starting point of this change of paradigm. Making a full history of the beginning of organic chemistry, albeit very interesting, is not the subject of the question. $\endgroup$
    – Amon
    May 6 '20 at 17:32

Not the answer you're looking for? Browse other questions tagged or ask your own question.