Why are organic reaction mechanisms so much more popular than inorganic mechanisms? When I come to think of it, what is a reaction mechanism? How can we use an arrow? Is it a rough approximation of the real picture i.e. the true quantum mechanical picture?
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$\begingroup$ No, inorganic reaction mechanism are also popular: chemistry.stackexchange.com/questions/10959/… $\endgroup$– Nilay GhoshJan 21, 2020 at 5:37
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$\begingroup$ chemistry.stackexchange.com/questions/125767/… $\endgroup$– Nilay GhoshJan 21, 2020 at 5:38
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$\begingroup$ chemistry.stackexchange.com/questions/65044/… $\endgroup$– Nilay GhoshJan 21, 2020 at 5:38
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2$\begingroup$ There is a simple answer: there are a lot more organic reactions because there are a lot more organic compounds than inorganic ones. This is a simple result of the enormous variety of molecules than can be built from carbon skeletons. Nothing else in the periodic table comes close. $\endgroup$– matt_blackJan 21, 2020 at 10:56
2 Answers
I believe a similar question had been asked before. Most inorganic reactions take place in aqueous media in their ionic form, and the substrate is simply not complex enough to warrant a reaction mechanism. As far as I know, mechanisms do exist for Coordination compound reactions.
You might want to check out this book which explains inorganic mechanisms using the arrow-pushing mechanism seen in organic chemistry.
If you have a look at the main types of reactions in inorganic chemistry (here I am only speaking of the common ones):
Redox reactions- These electron exchange reactions are often so fast, and so spontaneous, with K values of higher powers of 10. It hence becomes very difficult to have a 'mechanism' for them, as an important part of a mechanism is knowing what happened in the time the reaction was proceeding (the study of T.S., reaction intermediates, etc.). Thus such fast reactions we say occur in a single step and do not have a mechanism. The truth is, that there are just so many reactions of this type, that this becomes a common misconception.
Ligand substitution reactions- These do have proper mechanisms in place and various concepts to decide what happens first, who leaves better, whos substitutes better, like trans effect to name one such concept.
Organometallic reactions- Well as the name suggests, they, of course, do have mechanisms, and I won't go in great detail as to what those mechanisms are, you can see it here
Types of organometallic reactions:
Ligand dissociation / association Reductive elimination / oxidative addition Intramolecular insertion (e.g. CO migratory insertion) / elimination (e.g. β–hydride elimination) Metallacycle processes (e.g. σ-bond metathesis) Nucleophilic / electrophilic addition and abstraction are also possible, similar to organic chemistry.
- Combination, displacement, double displacement- These are often so simple, that ion-exchange, etc. are the only things that happen in them. So they also most of the times do not have a mechanism.
Hence, the common misconception is that these reactions never have a mechanism, but as you can see, that is not entirely true, but in most curriculums of inorganic chemistry, you will not learn 2. and 3. at a basic level, hence it is fair to be having this misconception.