Sciencemadness Discussion Board

All possible oxidants, reductants

vimal - 1-2-2005 at 17:52

Hi
I am trying to list out all possible oxidants and reductants used in organic chemistry synthesis. i listed out about 23 in each. can you figure out more?

also, please note that i have included CrO3 and Cr2O7 -- in a single group. and, MnO2, KMnO4 etc in a single group... :)

the rest ... ?

chemoleo - 1-2-2005 at 17:54

How about you first post all the oxidants you figured? Then we work on from there...no? Seems to make sense to me.
Apart from that.... what do you classify as oxidant- sometimes really obscure reagents still act as oxidants, because the system is easily reduced.
It's a tricky subject....

Synopsis - 1-2-2005 at 18:06

You cannot *list* all possible oxidants or reductant. Any molecule you can imagine is at the same time oxidant and reductant, just as all molecules are acids are as well as bases.

The important things are what reacts with what, why do they react as such and how can we use it. You could take thoses chromates and manganates examples of yours, find some utility to them and how they work and post the information gathered. More oxidant/reductant would then be posted and something usefull might comes out of this collective effort.

[Edited on 2-2-2005 by Synopsis]

vimal - 1-2-2005 at 18:13

ok. i will post my list in few days time. because unfortunately i have misplaced that book!

surely this would be useful... !

BromicAcid - 1-2-2005 at 18:26

There is a post around here somewhere where it was attempted to make a list of oxidants and place them in order of their oxidizing power, but it was abandoned partially due to the differing power of oxidizers depending on the conditions under which they are allowed to work. Despite that it would be a good place to start, I will see if I can dig it up.

Edit: Link
Me being interested in high oxidation state compounds could add quite a few although their practicality would definately be in question.

[Edited on 2/2/2005 by BromicAcid]

chemoleo - 2-2-2005 at 15:08

You might want to have a look at this, it gives a fairly comprehensive list of common oxidising and reducing agents which are used in organic chemistry.

This site is very useful btw!

vimal - 3-2-2005 at 07:44

Here is my list! and thanks for the site...

OXIDISING AGENTS
KMnO4, H*/HO~; MnO2
H2CrO4, CrO3/Ac2O, K2Cr2O7, H*
Tollens
Fehlings
Benedicts
Fentons (FeSO4, H2O2)
O3
DMSO (esp with Cl2 ...)
mcPBA
CrO2Cl2
Bi(NO3)3 (glycerol -> mesooxalic acid)
Br2/H2O (in biochemistry!)
HNO3
NaOI
HIO4, HIO3
HgO
HClO4
Ce(4+) with HClO4
H2SO5/H2S2O8
CF3CO-O-OH specifically used for aniline to nitrobenzene in one step.. rite?
Urotropine. -CH2-Cl -> -CH=NH
TiCl3
Bleaching by Cl2 :D
Fe***, Ce***
SeO2 (in oxidation of acidic enolic hydrogen)

phew...


Reducing:
1. and foremost... the electron :D
LAH
NaBH4, NaBH3CN
9-BBN
B2H6
DiBAL-H
TtBAL-H (tri-terbutylLAH) :)
Ni/H2, Pt,H2 etc...
HI
HCHO/NaOH
Sn/HCl; SnCl2
Fe,steam
Zn/NH4Cl, Zn dust, Zn+EtOH (or any metal that can liberate hydrogen say!)
Hydride ion ... this shouldnt be at this postition!
KOH,glycol
hydrazine
liq NH3/Na/Li (birch redn)
Mg(Hg)
NH4HS,NaHS,Na2S,(NH4)2S
H3PO3, H3PO2
Na2SnO2, Na3AsO3 with HO~
Al(i-Pr)3, iPr-OH (MPV redn)
bleaching by reduction... SO2 :D
Silanes...
Na/EtOH.. again metal which liberate Hydrogen


well...anything else?????

also, any idea WHY (NH4)2S reduces only one nitro group specifically?


Thanks!

vimal - 16-2-2005 at 20:19

So, does anyone find this list useful? Or does anyone have a more exhaustive collection?

BromicAcid - 17-2-2005 at 00:10

The list is interesting, but hardly useful. What it needs is to be done not in a list but a series of successive entries ranking comparative oxidative and reductive potential (not a big point because it varies so much under different conditions but always good to know just as a rule of thumb type deal) along with balanced half reactions, sources of materials, and their common applications / special properties. The list itself would just be suitable for a table of contents. Plus it is missing many items, just a customary glance and I notice that for oxidizing reagents you're missing the obvious fluorine, and you only mention bromine in water (adding bromine to aqueous base is incredibly strong oxidizing as is chlorine to aqueous base), fluorine isn't even mentioned (although really not a home item for organic chemistry, still it has its importance industrially) nor is elemental iodine (although only weakly oxidizing) although I understand not listing the rarer oxidizing reagents, ferrate, bismuthate, etc. As for reducing agents it's odd that azide would not be on there as it is somewhat readily available and an incredibly powerful reducing agent or the sodium potassium alloy which is stronger then either alone.

My point being, the list is neat, but this is really a long term project, I wish you the best.

[Edited on 2/17/2005 by BromicAcid]

vimal - 18-2-2005 at 08:08

Bromicacid,
I mentioned only the oxidising and reducing agents used frequently in organic chemistry!

But, how does an azide behave in organic chemistry? The only reaction I had seen so far involving azide in Organic is:

R-Cl + NaN3 -> R-N3 + NaCl
R-N3 + H2 / Pt -> R-NH2

The above method is a good one if one wants to produce only a particular amine instead of a mixture ...

Any where else??
Oh, I had forgotten. HNO2 also comes as OA :)

I am a fish - 18-2-2005 at 09:48

Quote:
Originally posted by BromicAcid
There is a post around here somewhere where it was attempted to make a list of oxidants and place them in order of their oxidizing power, but it was abandoned partially due to the differing power of oxidizers depending on the conditions under which they are allowed to work.


Even with that problem, such a list could still be useful. For example, the reactivity series of metals isn't absolute, but it is still a useful guide.