Overnight the mix turned a golden clear. The researcher might have been off about the smell of chlorine. It smells now of ester and -ene(toluene? crap). The researchers senses might have been a bit rattled by the 2ft tube steamroller prope dope hits. Or the hours of frenzied masturbation. Or both.

The mix was made strongly basic and refluxed for 2hrs. It turned brown. The mix was concentrated by distilling off water+yet to be determined players.

Anything that can be separated from the concentrated mix will be, then the mix made strongly acid by HCl and hopefully precipitate some PAA. Might even try to get the NiCl2 back or re-use it for the next test directly.

Now, how does one tame this reaction and turn it into the very best kind, the kind you can set to stir, go to bed, and wake up with product?

The researcher says bleach/sodium hypochlorite(NaOCl) must be changed to pool shock/calcium hypochlorite(Ca(OCl)2). The hypochlorite is our terminal oxidant and therefore can be used to stop this bitch automatically. Problem with bleach is that when the bottle says 5% or 6.5%, it actually means that they have put a shitpile of it in there so that after months on the shelf and it breaking down it will still have at least that much. Eff titration! As the hoes say, "We want E-Z!". So pool shock is easy.

The researcher will continue the chem wasting and report back with the outcome of the current and the planned experiment.

If this has been covered on another board, please point it out. It sucks to learn the hard way when someone else already has.

I assume aqua regia makes nickel chloride from nickel metal?

Oh, and since it might be of interest...

Abstract from the attached paper:
Upon exposure to commercial bleach (~5% aqueous sodium hypochlorite), nickel(II) chloride or nickel-
(II) acetate is transformed quantitatively into an insoluble nickel species, nickel oxide hydroxide. This
material consists of high surface area nanoparticles (ca. 4 nm) and is a useful heterogeneous catalyst for
the oxidation of many organic compounds. The oxidation of primary alcohols to carboxylic acids, secondary
alcohols to ketones, aldehydes to carboxylic acids, and a,B-unsaturated carboxylic acids to epoxy acids
is demonstrated using 2.5 mol % of nickel catalyst and commercial bleach as the terminal oxidant. We
demonstrate the controlled and selective oxidation of several organic substrates using this system affording
70-95% isolated yields and 90-100% purity. In most cases, the oxidations can be performed without
an organic solvent, making this approach attractive as a “greener” alternative to conventional oxidations.

Experimental section from the attached paper:
Standard Procedure for the Oxidation of Primary Alcohols
and Aldehydes. A 500 mL flask was charged with NiCl2 hexahydrate
(0.27 g, 1.14 mmol) and water (5 mL). A primary alcohol or
an aldehyde (45 mmol) was added followed by (optional) dichloromethane
(15 mL). The reaction was cooled in an ice bath, and
cold bleach (300 mL) was added in a steady stream over 5 min. A
fine black precipitate formed immediately. The resulting slurry was
stirred for 2 h at 0 °C and 2 h at room temperature. The slurry was
then acidified with 2 M hydrochloric acid until the aqueous layer
was strongly acidic by pH paper. The aqueous layer was extracted
with diethyl ether (3 x 100 mL). The combined organic extracts
were dried over anhydrous MgSO4 and filtered. Removal of the
solvent by rotary evaporation and brief high vacuum gave the crude
product. The purities could generally be improved to >98% by
distillation of the crude product or by recrystallization in the case
of solids.

Yes, the researcher strayed from the plan. This was on purpose. First, this uses a lot of bleach and then in quite a "green" way, uses as much solvent to extract the mess as bleach was used. Not very green! The researcher succeeded in getting a feel for this and also in verifying where the improvements can be made.

If someone could post a better idea of the equations of what is going on in this reaction, it would be appreciated.

Cheap, fast, not spewing death way to oxidize alcohols and aldehydes and nobody cares? Hmm...

EDIT---> Thank you to whoever found this ref. Probably java. But also whoever asked for it. Good stuff!

Its interesting, I am unfamaliiar with nickel oxide hydroxide, I plugged it into wiki and got this
http://en.wikipedia.org/wiki/Nickel(III)_oxide.

The reaction youve written beiing
6 NiCl2 + 4 NaOCl + 2 H2O -> Ni3O2(OH)2 + 4 NaCl + 2 HCl + 2 Cl2

If nickel has been oxidised then it would have to be 2+  >   3+ therefore having Ni3O2(OH)2  being (3)nickel +9 with 2 Oxygen -4 amd two OH being -2 therefore total is -6 which is along way from -9 which youd have to have to counteract the +9 of the nickel. The wiki article suggests NiOOH, which is Ni +3 and Oxygen -2 and OH -1 total being -3, which fits the bill. Also if you have a hydroxide ion OH in the product side, as well as HCl ect, your going to produce H2O and Cl- and if youve got an oxidant in the mix, you might of smelt Cl2, which overal may account for neutral pH.
Also youve got 6 NiCl2 on the reactant side with only I nickel of the nickel oxide hydrocide, on the product side. I am somewhat passing through, and hope what I have said is so. I am sort of rushed, but will come back to it.

ziggy

This molecule is unfamiliar to me, best I read the article in full, and not jump to conclusions to soon.

Just brieflly it seems that the nickel Chloride > nickel oxide hydroxide acts as a catalyst as its stated, so the oxidant is the HOCl -
so the products would be H2O and NaCl. and the insoluble Nickel oxide hydroxide. I think. Its very interesting use of reagants

" While exploring the scope of this
reaction, we observed several unusual reactions. Initially, our
principal research interests were in applying nickel oxide
hydroxide/NaOCl toward epoxidation catalysis. This catalyst
system does not react with most standard olefins such as styrene
and 1-hexene. However, as previously discussed, R,â-unsaturated
carboxylic acids are readily epoxidized. We reasoned that
the acid functional group was binding to the surface of the
heterogeneous catalyst and thus positioning the olefin to accept
an oxygen atom. The requirement of a directing group would
explain the inertness of standard olefins."

Sorry I missed this thread, I do like a good experimental!

"Regardless of the complicated dance that is actually going on, the oxygen from NaOCl is what ends up oxidizing the target, I guess"

Indirectly;

Nickel Oxide Hydroxide, is what oxidizes the alcohol. Adding catalytic amounts of Nickel(II)Salts in excess sodium hypochlorite generates and regenerates NiOOH, it is stated in the paper that "it is reasonable to assume that oxidation is occuring on the catalyst's surface".

Please post your exact method Disposable Stirbar (important to include how much reagents you added), as if it is similar to the modifications you made on the procedure I can see why it failed. First off you seem to really want this to be an overnight reaction, which it is not!! It goes 4 hours max!!!!!!!!!! 2 hours at 0*C no higher, and 2 hours at room temperature NO HIGHER!!!.

You were doing things that seemed to me to be crazy, like after letting it sit for like 20 hours you then refluxed with NaOH I am sure I did not read that in the experimental, if you want something to work follow the procedure in the paper to the letter. You were asking why the post reaction solution is not acidic is because hypochlorite raises the pH, after the reaction is complete you need to protonate the negatively charged oxygen on the carbonyl terminus that is currently a soluble sodium salt hence adding HCl. The reaction makes perfect sense until you start changing things, calcium hypochlorite is more stable and less soluble than its sodium analog (two reasons it will be inferior in this reaction). And the sodium ions are preferential to have floating around in this reaction, as they end up on the carboxylic acid as a soluble sodium salt which keeps it in solution where it can react with the reagents, after the reaction is finished HCl addition which protonates the carboxylic acid which forces it out of solution as an oil where it can be worked up. Also the researchers in question will have rotavaps so all their solvent would be recycled.

btw; If after 2 hours at 0*C and 2 hours at room temperature, you acidify the black nickel oxide solution. And still receive benzoic acid, you have benzyl alcohol and not 2-phenylethanol.

"I think it can be used with secondary alcohols > ketones, but requires a proton source to form HOCl"

It can be, but does not require a proton source. The reaction is nearly identical, but you can see in the paper the acidic work up is missing for ketones! As you can make a sodium salt of a carboxylic acid, but not a ketone. So it is unnecessary to add HCl, as you will not be adding a proton and can extract it with non-polar solvent as it is. Whereas most carboxylic acids will become a water soluble sodium salt, and need to be neutralized with HCl before being worked up with non-polar solvent. That is the only reason they use HCl in THAT procedure!

You would now be referring to the paper below, which proceeds via a different mechanism consistent with what you where talking about. Primary alcohols generally give esters with that method (although benzyl alcohol gives benzaldehyde), and the use of the more stable calcium hypochlorite can be beneficial. But secondary alcohols can also be oxidized to ketones with NiOOH as well as oxidation of aldehydes to their respective carboxylic acid and epoxidation of a,b-unsatured carboxylic acids.;

Convenient and Inexpensive Procedure for Oxidation of Secondary Alcohols to Ketones
Stevens R, Chapman K, Weller H. 1980
J. Org. Chem
45:2030-2032
http://www.quimica.ufpr.br/armo/experimentos/oxidationNaOCl.pdf

The Oxidation of Alcohols and Ethers Using Calcium Hypochlorite
S.O. Nwaukwa and P.M. Keehn
Tet. Lett. 23(1), 35-38 (1982)
http://thevespiary:depidyhk@www.thevespiary.org/rhodium//Rhodium/chemistry/ether2ester.hypochlorite.html

So a standard run should go like this, right:

0.27grams of NiCl2 *6H2O with 5ml of water, 45mmol of primary alcohol is added. 2-phenylethanol mol weight= 122.16g/mol, with a density of 1.017g/cm3 so 5.4ml is added. The solution cooled in an ice bath and 300ml of 5% NaOCl solution added over a 5 minute period, they note a black precipitate they refer to the mass at this time as slurry inferring it is paste like! is stirred at 0*C for 2 hours and then at room temp for 2 hours. The slurry is then acidified with 2M HCl (7.3%) until strongly acidic (pH 2), extracted with non-polar solvent. 

"I still defend that there is too much bleach and that things don't have to go that fast."

300mls of 5% NaOCl means there is around 15grams of NaOCl in that 300ml, to 5.5grams of primary alcohol a less than 3 fold excess! And they clearly state in the paper that if you cut down the bleach you have increase the nickel oxide hydroxide content to stoichometric quantities. Using just catalytic amounts of NiCl2 you need that excess which is less than a three fold one. You could increase the hypochlorite concentration from 5%, but this may have deleterious effect on the aclohol. And bleach can be bought over the counter by the gallon cheaply, you need vigorous conditions to do anything to primary alcohol and calcium hypochlorite may not have the power to generate the NiOOH in sufficient quantities. The researchers studied this reaction and came up with the best conditions.

"I can tell you that if I had a load of gravel to bring to my house I would take it all in one go in a truck, not a stone at a time in a ferrari, no matter how cool it looks to go fast."

But running small pilot runs to test you have the reaction right and proving the concept, before putting all your eggs in one basket is smart in chemistry. As it sometimes take a couple of runs to get the max yield, and to iron out inevitable problems. But hey, no one ever said you could not add the reagents to a large garbage pail and then slowly add 30 litres of bleach, stirring with a concrete mixing drill bit. After the reaction take out large aliquots to acidify and work up in a more appropriate vessel, I had never mentioned any labglass just that you should stick to the paper! Once you have proved the concept and received the yield quoted, by all means experiment and try and improve it (but it is better to do this on a small scale as you can do more reactions at one time without wasting a truck full of gravel to realize you did one little thing wrong that had you known prior you would not have done).

"For good science, this will be run at exactly the scale of the ref, following the directions exactly for the solvent free variation and reported. I hope that under control it will make PhEtOH->PAA. If so it will immediately lead to the disposable stirbar Vespiary edition(TM) pool shock variation."

Awesome! Thanks, I look forward to it! Also I just thought that the solvent may help you here as you said it can get solid, a solvent by definition would fix that!

If its getting warm on the ice bath you need slower addition of NaOCl, as you are adding it to quick. Also they are just neutralizing the solution with a 2M HCl buffer, so although phenylacetic could handle much higher concentrations it is not standard practice to neutralize with conc. acid. 

"5% is that isn't what's actually in the bottle"

You are right but it is an estimate that for a 5% solution will be nearly spot on so gives a good idea of the ratios needed. If you have a solution with a known higher concentration I would dilute it down to 5% accordingly before the reaction as thats what the paper calls for and any excess will generate more heat.

Cool. I have had bleach in the beer fridge for 3 days now. I just haven't got around to doing the deed. Thanks.

EDIT-> These bastards! "Commercial bleach (ca. 5-6% aqueous NaOCl) was sparged with nitrogen for 5 minutes immediately before use."
That is one line! It was integral to the procedures done but not put in the procedure! Dicks! I remember reading some old hive bee going on about always degassing everything because that's what all the labs do even if they aren't writing it. Does it make a big difference? I don't know but I can assure you nitrogen sparging wasn't done because it wasn't written in the experimental section. It would be removing the free chlorine, I think

I would have used NaOCl but.... I can't friggin find it(...)

Can't find bleach? heh

Thanks Sedit, that is really interesting. I think the observed colors are strange(quickly coming back to green), so perhaps this is proceeding through a different mechanism. As long as hydrogen peroxide has the umph to form the same nickel oxide hydroxide oxidant, it shouldn't really matter which terminal oxidant is used, and there might be many choices. Could the the experiment be repeated with a distillation or try for a bisulfite adduct?

Someone was nice enough to upload Hulickey's Oxidation book and I have been going through that. Lots of good stuff but what a bitch without a table of contents included in the djvu.

This really is on my todo list. I will report back, good or bad. And remember, that my "bad" wasn't really bad. As far as oxidations go, this one is easy, fast and safe. It still has the benzyl side chain oxidation question hanging over it, but we will get to the bottom of it soon!

BTW can this substance be isolated to produce concentrated AcOH from EtOH perhaps?

Which substance, nickel oxide hydroxide? Right in the ref they say that this is a mod to use the nickel chloride in catalytic amounts and that the old tech was to form a bunch of it, so I guess the answer is yes. I don't know what sort of luck you will have with it, though.