Which Reducing Agent is the Best?

[@jogandsp]

As an inorganic chemist who does a lot of electrochem, I'm going to have to file a formal complaint about electricity not being in S tier. It has (theoretically) unlimited reducing potential! Just crank the voltage up lol.

[@That_Chemist]

haha

[@alexwang982]

@@EddieTheHit’s extremely unselective and messy sadly

[@__lasevix_]

Electricity is the best one because it's not regulated 😊😊 (I'm referring to Birkekand-Eyde type nitrate generation in countries with strict energetics regulations)

[@zahariburgess3660]

@@__lasevix_I need to build me one of those

[@avagadrhoe768]

i love the tingle when i lick the last bits of LiAlH4 off the spoon

[@koukouzee2923]

I was ready to start ranting about why sulphur is in S tier (you are a sulphur/fluorine chemist) but I apreciate you being fair

[@That_Chemist]

Honestly, elemental sulfur is so annoying

[@ugiswrong]

🥺

[@Nicolas-qk7lt]

A little info about reducing agents for biochemists. DTT can reduce nickel in the Ni-NTA resin which was used to purify 6*histidine-tagged proteins, but TCEP and B-ME won't reduce it at low concentrations. Also, DTT and B-ME both have a very high refractive index which can interfere with many assays, and they release a lot of heat when oxidized so cannot be used in anything that measures enthalpy. TCEP is usually the go-to reducing agent for most biochemical assays and it doesn't smell like ass. I would rank TCEP as S tier for biochemists the only drawback is its price, B-ME, and DTT as D tier.

[@griffing2523]

wait this is so useful to know, I didn't realize DTT can interfere with an Ni-NTA column

[@elnombre91]

You can buy LAH in ~0.1 g pellets which is what we use at my company. Depending on the compound being reduced and the scale you can need to stir the pellet suspension out for a while to break up the pellets but they're a lot safer option than using the powder and are more convenient than the solution. I've run LAH reductions on large scale using ~20g + of these pellets without issue.

[@That_Chemist]

Awesome

[@pmathewizard]

I can't wait to spend 30% of our country's science budget to prove the reducing power of the carrot

[@DavidSchilter]

Nice one! Yeah, C is obviously used on large scales for smelting. Perhaps one common reductant that I would like to see mentioned is the even more reduced form: KC8 (potassium graphite). It's very convenient on the research lab scale because you can filter off the graphite byproduct to leave the reduced species. Of course, there are lots more reductants (e.g nBuLi is good for inorganic solids, gives octane) but this is a nice list.

[@elnombre91]

KC8 is great, it's a good synthesis for new inorganic chem PhD students too.

[@Kall1208E]

I like KC8 so much I even decorated the ceiling of my lab with it xD

[@jonored]

Interestingly, C sort of isn't used directly to reduce stuff other than oxygen in most smelting; C is just a way to get heat and CO. It can't easily get in close enough contact with the ore, you need the intermediate CO step that does the work.

[@DavidSchilter]

@@jonored Interesting! Yeah - the mechanism of smelting would be very interesting (and difficult!) to study.

[@TNTLuc]

As a chemist working in wet chemistry analysis, I was so happy to see my boy Sodium thiosulfate in S-Tier. And isn't ascorbic acid in soda sometimes? Or just in other food? If it's in soda it should be S-Tier.

[@That_Chemist]

That is true

[@marianeptune7321]

Sodium Thiosulfate deserved S-tier just because you can get that shit in any pet store

[@HiwasseeRiver]

I'm glad you mentioned solvated electrons (Na in NH3). That could star a video of pretty solutions, the bronze solution looks alive.

[@jordanliles7256]

Ascorbic acid and it’s conjugate base are actually used quite a bit in CuACC chemistry for copper reduction!

[@ondrejczechaczek6822]

I love how you evaluate these tier lists. Now as a fan of process chemistry I would LOOOOVE to see tier lists for lab and for large scale.

[@gamingmarcus]

Tier list suggestion: best metals/elements for catalysts. Palladium GOAT of course.

[@That_Chemist]

I mean, Tom from explosions and fire already did one!

[@gamingmarcus]

@@That_Chemist But he only ranked the elements in general, didn't he?

[@robertlapointe4093]

Nice list. Sodium amalgam was my goto reductant in grad school (for making Nb(III) and Ta(III) organometallics). Sodium naphthalide is also a great reductant and can be prepared in-situ. NaK is also useful, although a little sketchy if you don't have a glove-box. Lithium powder can be transferred in a nitrogen glove-box, just keep it in a Schlenk flask under argon for storage and use Schlenk techniques under argon/vacuum for reactions (made a lot of neopentyl lithium that way).

[@That_Chemist]

Is lithium really still chill under N2? Did I overhype it’s sensitivity?

[@robertlapointe4093]

@@That_Chemist At normal glove-box ambient temperatures, the reaction between lithium powder and nitrogen is pretty slow, it is not going to spontaneously combust. Give it a week or so and you'll have plenty of nitride, but probably not full conversion even then.

[@DavidRobertsonUK]

I once used freebase hydrazine as a TLC stain. People thought I was crazy but it worked. (I wanted to check if a spot was 2,4-dinitrochlorobenzene)

[@That_Chemist]

Wow

[@borwinbandelow2781]

Haha nice. Next time try tBuLi like a proper madman.

[@alvinkwok587]

I think u technically forgot one, Ammonia, it's not able to reduce anything but it can quench oxidation reaction pretty quick.

[@kevinlatulippe6944]

Ammonia gas can reduce certain metals but not aqueous ammonia

[@sealx2292]

I really thought argon glove boxes are common practice. AC, PC and OC labs have those in my university. We are using lithium all the time (but for batteries to be fair). N2 should not be to bad. There is a dry room built in a new facility next to our institute. Li should be fine in this enviorment. O2 and N2 should not be a big problem.

[@AlexBesogonov]

Carbon monoxide is a key reagent in carbonyl processes, that we will use one day to mine asteroids. Very underrated.

[@dillhuang5988]

No hydroquinone or caffeic acid, aromatic reductants need some love too!

[@dillhuang5988]

BTW, TCEP is much nicer to work with than 2ME. Apart from the lack of vile smell, it also has a vastly longer half life in dilute aqueous solutions and it is a lot less likely to react with metal cations. Never gave much thought about toxicity, but we usually only have to use 1mM to 2mM concentration in working buffers.

[@janmelantu7490]

Anything that can act as a photographic developer is S-tier in my book, it’s why I would put Vitamin C in S-tier

[@diablominero]

Gotta get your antioxidants! [sprinkles sodium borohydride on food]

[@oM477o]

The only thing I know about antioxidants is some health foods claim to have them. I don't think many of the chemicals on this are very healthy though

[@That_Chemist]

True

[@petersmythe6462]

Potassium is healthy... as an ion... not so much as a metal.

[@danielaustin7643]

our lab uses so much raney Ni, i absolutely hate the stuff, its a bit scary due to anecdotes of people having fires with it. its a pain to filter, we then quench the celite + Ni with HCl then neutralise the acidic solution with NaOH to precipitate then we spend the next 2 days filtering off the Ni(OH)2 + celite to dispose of in special Ni waste. it comes as a slurry in water, we use it we don't measure it out we just take a broken glass pipette and add x pipettes of the slurry at some random amount. reactions are are super unreliable and can take anywhere from 12 hrs to 10 days on the same substrate under the same conditions.

[@klondikesaloon7026]

Yeah, I much, much prefer palladium on carbon over Raney Nickel, but then again I'm not paying for it. I wonder how the cost breakdown changes if you spend time recovering the Pd instead of dealing with the nickel priority pollutant waste. And yeah, Raney nickel is quite capable of sparking if it dries.

[@danielaustin7643]

@@klondikesaloon7026 we are constantly reducing nitro groups on a 20g scale using ra-Ni, i just wish we could use Pd for it.

[@danielaustin7643]

@@michaelanderson4849 the acidification is purely to quench and disposal

[@klondikesaloon7026]

@@michaelanderson4849 Raney nickel itself is pyrophoric when dry, often even after a reaction. We just rinse the filter cake with water to remove solvent traces before sending it out for disposal; it sounds like they're completely deactivating it themselves prior to sending it out, might depend on their vendor/nickel waste routing.

[@That_Chemist]

I’ve only used it in the context of Mozingo reductions

[@aluminumchemist2586]

You are missing KC8. It is very simple to prepare and very efficient reductant. You can remove it easily as well. The only downside is that it must be used under inert atmosphere, ideally inside a glovebox.

[@jacobtierney4419]

I gotta put a word in for TCEP; it's a non-sulfur biofriendly reductant which is a big boon if you are doing biophysics with thiophilic proteins where b-ME or DTT would interfere. Gotta be C tier.

[@jacobtierney4419]

Also it's di-thio-threitol

[@user255]

TCEP should be in E tier, because it is pretty much nice version of mercaptoethanol (which is in F tier).

[@melonmusk684]

But... But ascorbic acid is in soda! how dare you not put it in S tier?!

[@That_Chemist]

F

[@davidthane9002]

Potassium ferro cyanide is used for enantioselective dihydroxilation (sharpless dihydroxilation) as sacrificial reductive agent to regenerate the osmium. So really useful. Sodium triacetoxyborohydride can be used for stereoselektiv reductions as well.

[@nab-v1w]

As a non native english speaker, i thanks you a lot for adding all names to coumpounds ! Take care

[@defenestrated23]

Need to do a TLC Stain/resolver tier list next!

[@georgeretsides4293]

Samarium iodide is so cool man. You can use it for crossover reactions. Form a radical which does radical chemistry until there are no fast radical reactions and then it can crossover via a second electron transfer to form organometallics that do polar chemistry.

[@hcn6708]

5:50 it's in (some) Sodas tho

[@defenestrated23]

STAB definitely goes in S tier. It's great to work with, workup is straightforward, and really nails that sweet spot of mild to medium strength reduction. I don't see iron as being S tier, literally never used it in 8 years of chemistry (pharmaceutical synthesis at pilot scale mostly). seems like a pain to remove, but at least it's harmless. I'd give it B tier at best.

[@Finnnicus]

not an iron fan either but its sometimes good to make anilines on a mole scale. workup by precipitating iron hydroxides with base then filter through a frit, extract filtrate.

[@edgaracosta9976]

Man you mentioned something that was quite interesting about the reduction of nitro groups. Would love if you could make a video about nitro reduction in more detail!

[@That_Chemist]

I think I did in my IOC series - if it isn’t on this channel, it’s on my old channel - if it isn’t there, DM me on discord and I’ll add it to my list

[@edgaracosta9976]

@@That_Chemist thanks man! Just joined your discord! I also wanted to ask what reducing agents you think are the best to work with Enzymes and are not toxic for them ?

[@revenevan11]

Ascorbic acid is very underrated! I was surprised to learn of its reducing power when I was younger and doing some hobby chemistry. I actually used it in a faster burning "flash powder" kind of composition, to pop open the parachute of a diy model rocket 😁 It's surprisingly willing to go off when mixed KNO3, but isn't too sensitive. The mixture did seem to partially degrade over time in air, and turn a purple-ish color, but that may have been impurities since I extracted the vitamin C out of store-bought tablets.

[@avael2451]

Raney nickel alloy is actually usable as a reducing agent as well, I was surprised to learn this recently and I'm planning to use it in an upcoming synthesis actually- it's quite a useful reagent, much moreso than i was led to believe in university DOI of a review on the subject from 1989: 10.1021/cr00093a002 Edit: One note on solvated electrons, there's been some work done recently like the electrochemical birch reduction at Scripp's that actually manage to solvate electrons electrochemically. ACS Sus Chem and OPR&D tend to have a lot of interesting papers on electrochemical reductions.

[@That_Chemist]

I’m aware - but it’s mostly just his group doing the work, and I would like to see wider acceptance before considering it versatile

[@2001Pieps]

I both despise and commend you for that title. I can't wait for KZbin to recommend this to the wrong people looking for health advise.

[@Yourlocalbacterium]

This is a tier list, not a video for health advice

[@koukouzee2923]

heartburn ? take some AlHg !

[@That_Chemist]

Not getting on the antioxidant hype train is good for your health

[@sealpiercing8476]

@@That_Chemist I will get on the oxidant hype train. Oxygen is a good oxidant, and it's free, so I will do exercise in order to breathe more oxygen. Oxidants are good for your health.

[@petevenuti7355]

​@@sealpiercing8476 some people drink h2o2 to oxygenate ....

[@menjolno]

18:59 ad plays while you made 2 mistakes of switching tabs

[@That_Chemist]

dang it

[@kool-aidman5874]

Watching this as a 10th grader who’s gonna be headed into chem 3202 (second level high school chem here in Canada) this both interests and terrifies me for what’s to come

[@That_Chemist]

Good :)

[@alextopfer1068]

As an amateur blacksmith I also give Iron an S (for scale)

[@jimparsons6803]

Liked the Fe, Zn, and electricity. Never did electricity, though. Read some books that one of my Professors suggested, as he was an Electrochemist. Pretty slick, I thought.

[@skyethebi]

26:44 I think it might be worth talking abt metal carbonyl compounds. You can use carbon monoxide but in a much more handleable form.

[@montoyaadam123]

Triethyl silane is so versatile. Examines, imines, aldehydes Benzyls alcohols. One of my favorites

[@That_Chemist]

GOAT

[@ArichManas]

TCEP is also used to treat ultrapure water (along with autoclaving) to make the water nuclease free, so it can be safely used while working with DNA/RNA

[@nathanroyer1844]

the ascorbic acid is really good for quenching Iodine form reactions like in solid phase peptide synthesis when is a cys-cys bond in the sequence.

[@assaf127]

I once had a very sensitive compound that was very cleanly reduced with (Me2N)2C=C(NMe2)2

[@That_Chemist]

TDMAE ftw

[@kingnotail3838]

SnCl2 in refluxing ethanol is my go-to for nitro-to-amine reductions

[@AA-gl1dr]

Mercaptoethanol is definitely F tier as in my gel electrophoresis didn’t work and I smell like cancer. F’s in the chat

[@Karol-bw3hb]

DTT is chill for mild azide reductions. Has also been used on resin in spps

[@Kualinar]

A good thing about hydrogen is that it's very easy to get it out of your experiment when you no longer need it.

[@esven9263]

No love for sodium erythorbate ? It's very similar to ascorbic acid but cheaper and it's used to make sausages so what's not to love. It's also used a lot at industrial scales as part of waste-water processing because it does a great job reducing things like hexavalent chromium to levels that can be dumped into the city sewers.

[@That_Chemist]

Cool!

[@alan2here]

Gosh, you can donate electrons (to reduce molecules) by using electricity.

[@Magistr_XoHHa]

My colleague prepared SmI2 once. He made a solution of it and stored it in the flask under argon, and every time he tried to use it he put and aliquote in the syringe, and then SmI2 oxidized, turning dark blue solution to light yellow even after light shaking of the syringe. It could not even be put in another empty flask under argon as the solution became yellow in a second. So it is unclear for me how SmI2 could be used

[@That_Chemist]

Air-sensitive techniques, or insitu preparation

[@iryanmadayana1904]

"Hmm, TDAE sounds like it might work for that one reduction I keep having trouble with, maybe I should-" >300 € for 10 grams ...oh. Hm. Heck. The triethyl silane +TFA combo... I should check what the scope and tolerance of that is.

[@That_Chemist]

TES/TFA is used A LOT - you can always make TDAE yourself - also 300 euros for 10 grams is a steal!

[@Evenaardez]

What does a low DR in a reduction mean?

[@That_Chemist]

Diastereomeric ratio between possible diastereomers that could form

[@Evenaardez]

@@That_Chemist Oooh gotcha, thank you!

[@peachypascal3944]

Soda because it reduces stress = S tier

[@inf0phreak]

25:12 dems some SHOTS FIRED! ;-)

[@DodgyWarfare]

what about blueberry juice?

[@griffing2523]

omg has anyone been able to figure out the identity of the ketoreductase in carrots

[@That_Chemist]

Great question

[@mathiasdaniels]

Wow, quite a long list. I'm a bit sad that I have only used about half of them. It's a bit surprising that rongalite didn't make the list as it is kind of a classic/old school reductant.

[@That_Chemist]

I forgot about that one

[@TheBackyardChemist]

You may be able to avoid heating K if you use NaK.

[@That_Chemist]

That is true

[@pmathewizard]

Wait anti oxidants are just reducing agents, da more you know

[@That_Chemist]

True

[@Nihilpotat]

Where's the carrot chem link 😭

[@That_Chemist]

Was the card missing? I’ll double check

[@Glaudge]

in his tier lists half of the items there is a very clear logical reason for it's placement but the other half of the items he places them for the memes e.g. "i'll put in in D for drugs""

[@That_Chemist]

100%

[@pmathewizard]

Wait, what are the difference between antioxidants and reducing agents?

[@That_Chemist]

None

[@Marcin_Kwidzinski]

Na in S-tier, K in C-tier, so NaK should be in A or B-tier?

[@That_Chemist]

NaK is so sus tho

[@salyxxe]

I might be blind but I'm surprised there's no Pd/C! I don't know much about it but it's quite tolerant to a lot of functional groups right?

[@That_Chemist]

It’s the catalyst

[@terrodar19]

Could you do anything with solvated electrons from sodium dissolved in liquid ammonia?

[@That_Chemist]

dissolving metal reductions (alkynes), birch reductions (of arenes)

[@Nicolas-qk7lt]

Glad to see some biomolecules 🤓

[@That_Chemist]

I have to give you guys some love haha

[@janmelantu7490]

That Chemist: “Tin compounds are quite toxic” Me, brushing my teeth with Stannous Fluoride: 👀👀👀

[@That_Chemist]

I mean, the moment I discovered that, I told my family to not use it

[@kaushalnaithani9859]

The concerntration at which Sn is present in toothpaste is very low (1000ppm), so it won't be toxic unless you are using 20 packs at same time

[@DavidRobertsonUK]

You're not really meant to swallow it either

[@cloud_congestus]

...zinc and iron are reductants?

[@jsmdnq]

Can you explain to me how, in chemistry, when reactions are done to modify things humans digest how a chemist knows that they did not create any dangerous chemicals in the process except by relying on the dogmatic believe that they didn't? How do they know they are not creating some substance, even if in minute quantity, that is actually causing serious damage, even if through accumulation, in to a human that consumes the after product?

[@That_Chemist]

It’s entirely possible - this is why they do toxicological studies when developing new drugs! Researchers are always faced with the possibility that the chemicals they are making could have completely unknown bio activities. Someone on the discord was saying how one of their colleagues made 100 grams of cycloprop-2-enoic acid, which (unbeknownst to them) is a potent mycotoxin that is lethal in milligram quantities!

[@morgan0]

carrots deserve s tier

[@willcarson6680]

Aren’t all reducing agents ultimately produced by electricity somewhere along the line? LAH requires either metallic lithium or sodium which have to be themselves reduced by another element or electricity. Weaker reducing agents require stronger ones which are ultimately prepared from electricity.

[@hellothere3163]

Any tips for aluminum hydride reduction work ups? The dibal quench and work up is a disaster due to formation of Al gel emulsions, and I’ve not had much luck with tartrate in breaking them

[@montoyaadam123]

Sometimes you need to stir the tartrate over night before you see two clean layers. I’ve had good luck using dilute HCl if your substrate can tolerate it as well. It’s quicker and I prefer it if I don’t have acid sensitivity issues.

[@That_Chemist]

Do the Fieser workup!

[@BuickDoc]

SABCDEF? I have seen that classification elsewhere. What are the distinctions between the levels?

[@That_Chemist]

S is super, ABCDEF afterwards in best to worst

[@marcopolo8584]

That Chemist, many sodas contain ascorbic acid, why isn't it in S tier?

[@ExMachiavellian]

You sound exactly like ‘Casually Explained.’ I can’t unhear it. You also started posting more when Casually Explained started posting less… 🤨

[@That_Chemist]

And he also has a degree in chemistry iirc

[@That_Chemist]

To be fair we live in the same Province, except he lives on the island and I live on the mainland

[@philipmanavado4566]

#justiceforcarrot

[@CatboyChemicalSociety]

Electricity S tier come one cuz electrochem reduction desu yo!!!

[@DavidRobertsonUK]

Hypophosphorous acid (or its salts) is critical in the manufacture of printed circuit boards, as it's used for electroless copper plating used to plate the inside of vias in PCBs.

[@snowdaysrule]

I always wondered why this compound was available on ebay from china despite it's prescence on the "naughy list" in the usa.

[@DavidRobertsonUK]

@@snowdaysrule you can also use it (and all of the D-tier) reductants for legitimate organic synthesis purposes....

[@ChronosTachyon]

Let's be honest, "oh, they use it all the time in the electronics and semiconductor industries" is not exactly a ringing endorsement of a substance.

[@DavidRobertsonUK]

@@ChronosTachyon PCB manufacturing is much more tame than semiconductor in terms of nastiness of chemicals

[@drantoswyrick396]

>Carrot not in S Unsubbed and blocked

[@humr2346]

Do you think tert-Butyl hydroperoxide would react with ascorbic acid?

[@That_Chemist]

It’s 50/50 - either it will or it wont

[@humr2346]

@@That_Chemist Is it not always like that? :D

[@dylanschmitt8622]

Why so harsh on lithium? I find it highly effective

[@jogandsp]

No hate, but it is abundantly clear that you're an organic chemist. I know you don't try to hide that or anything, it's just interesting seeing how your list differs from what an inorganic chemist's would look like. For instance, you don't even have cobaltocene or decamethylcobaltocene anywhere on your list??

[@jarmilnikolashynek]

Hair

[@taborsmrcna]

... only looking to the D tier :-D

[@emilyrln]

"Sulfur is very promiscuous." 😳 So it's in F tier because it, uhhh… gets feisty with other chemicals?

[@PaulSteMarie]

What the bloody hell is that "red aluminum"? It looks like two ions complexed with two ether-y chains, dunno the correct name with multiple oxygens.

[@the_kingslayer]

I really like that he says "species" and not "speshies"..... say it right people!

[@That_Chemist]

I totally do - wtf

[@That_Chemist]

I do it both ways

[@That_Chemist]

You broke my brain

[@MichaelClark-uw7ex]

Sometimes the simplest is the best. Atomic Hydrogen for the win.

[@awli8861]

Ag is still the best dude

[@stephenjacks8196]

Wrong. Phosphorus reacts with Iodine to form P2I4.

[@That_Chemist]

Does it stop though!

[@kevinlatulippe6944]

You are too smart

[@That_Chemist]

honestly I couldn't say the name of several plants correctly in the most recent video - I have MUCH to learn still

[@mauricehietkampmh]

Alane in C tier?!?? Disgraceful

[@rudolfmueller9145]

Zn/Cu works really well but is not on your list

[@SecretLars]

Dislike because Carrots in C for Carrot and not in S because it's so S for stupid. Like why would it work, and any so well?!