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Texium
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Welcome to the forum! You've come to the right place to ask such questions. Quote: Originally posted by SamuelLFraction  | For a start, there is not much literature on this reaction apart from chemplayer and an erowid text I believe. Chemplayer mentions in the video that
the reaction initially starts as thus:
Al + 3I --> AlI3
Am I correct in believing that since Iodine is diatomic, that it should be:
2Al + 3I2 --> 2AlI3?
Secondly, based off of this (if correct) the molar calculations are incorrect and have been calculated via simply the atomic mass of the element
Iodine, 126.9 , when diatomic it should be 253.8g/mol, since a molecule, no? This is not in any way, shape or form a way of trying to slate Chemplayer
at all, I just want to make sure my knowledge on chemistry is right. |
Yes, you're right that the true
balanced equation is 2Al + 3I2 --> 2AlI3
However, it doesn't matter which equation you use to calculate the amounts of reagents needed since both equations are still balanced in a 1:3 ratio
of Al to I. 50 grams of I and 50 grams of I2 contain the same number of I atoms, you see?
I don't have any other comments to make though as I haven't run this reaction myself.
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AvBaeyer
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Saturated primary (eg ethanol) and secondary alcohols (eg isopropanol) are unaffected by aluminum triodide. Allylic, benzylic, and tertiary alcohols
are regioselectively converted to the corresponding iodide by the reagent. There is little expectation that ethyl iodide will be formed with aluminium
triodide, at least in any useful amount.
Unfortunately, the chemplayer experiment is not useful. The product was not characterized (no boiling point). The identification of the product was
based on "it looks like ethyl iodide." Maybe there was some iodide formed but the experiment as it stands is non-informative and unconvincing.
For some useful information please see:
P Sarmah, NC Barua, Tetrahedron 1989, 45, 3569. "Regioselective transformation of allylic, benzylic and tertiary alcohols into the corresponding
iodides wrih aluminium triiodide: deoxygenation of vicinal diols"
AvB
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SamuelLFraction
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Zts - thank you for your reply, I feel a bit silly now realising this haha!
AvB - I'm glad to have an explanation for the relatively low yield I produced. It did have a boiling point of 73 degrees so at least all hope is not
lost with the questionable reaction, shame such a small amount but I'm glad to learn. I really appreciate you including the material of
regioselection, I now have something interesting to read and learn, thank you! 
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Chemi Pharma
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| Quote: Originally posted by AvBaeyer | Saturated primary (eg ethanol) and secondary alcohols (eg isopropanol) are unaffected by aluminum triodide. Allylic, benzylic, and tertiary alcohols
are regioselectively converted to the corresponding iodide by the reagent. There is little expectation that ethyl iodide will be formed with aluminium
triodide, at least in any useful amount.
Unfortunately, the chemplayer experiment is not useful. The product was not characterized (no boiling point). The identification of the product was
based on "it looks like ethyl iodide." Maybe there was some iodide formed but the experiment as it stands is non-informative and unconvincing.
AvB |
@AVBayer, you 're completely right when you say AlI3 doesn't affect primary and secondary alcohols.
Unfortunately many "ChemPlayer" videos at you tube are not trustworthy about the results and yields he claims. In my oppinion, in some experiments he
clear did work up mistakes that affected the yields and others experiments clearly suffers from conceptual matters, although his experiments appears
to be very instructive and interesting for the amateur chemistry.
I think he needs urgently start to use a LC-MS to make a qualitative and quantitative sample analyze, like "Nurd Rage" does.
@SamuelLFraction, if you intend to sinthesize alkyl iodides easily and with good yields, I suggest you the use of an alkaline iodide, phosphoric acid
and the alcohol (or ether, or alkene), at reflux, following the method I posted in the study attached below:
Attachment: Iodides from clevage of ethers or iodination of alcohols and alkenes with KI + H3PO4.pdf (328kB)
This file has been downloaded 571 times
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JJay
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I have occasionally questioned Chem Player's results (such as when I made p-aminophenol and experienced much more rapid decomposition than was
apparent in the video), but for the most part I think Chem Player demonstrates good science, and some of Chem Player's stuff is really cutting edge.
There is a tendency among YouTube chemists in general to avoid extensive characterization or to show only easy characterizations that support the
chemist's conclusion without ruling out impurities or other products. (For example, do you see any YouTube sulfuric acid distillation video that shows
an actual titration?) But I don't think that Chem Player is worse than NurdRage or Nile Red or any other YouTube chemist in this regard, and I don't
think it's caused by untrustworthiness so much as cognitive bias. There are very good reasons for peer review, after all....
That said, do any of the big box stores carry 85% phosphoric acid?
[Edited on 25-11-2017 by JJay]
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SamuelLFraction
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@Chemi Pharma, I did originally think it would be a lot easier to avoid the Aluminium route and go with phosporic acid, however, could not think of
where to accumulate it.
Luckily I have had an epiphany and realised it's easily found. (Also thank you for the material!)
@JJay phosphoric acid at 85% is available as Ph adjustment for cultivation, if you wanted to know. Perhaps I better not say product name as maybe
this is not allowed?
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JJay
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It is permitted, but I don't blast that sort of information on every thread either. It is up to you based on how you feel that information will be
used.
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Bert
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S.C. Wack
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The process is not unlike P and the alcohol is not supposed to be anhydrous, so the water makes HI.
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SamuelLFraction
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@S.C Wack, this may well explain why low yield then, since anhydrous ethanol was used. I will try the reaction again, this time with more elemental
iodine and dilute anhydrous ethanol until about 85%. I will report back with some figures if all goes to plan
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S.C. Wack
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The reaction is probably unlike P as now I look it up and see that calls for anhydrous alcohol. 85% you say have you read the original literature
calling for 84% ethanol.
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SamuelLFraction
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@ S.C Wack, oh well, I suppose in chemistry not everything works out to how you expect. Yes I have read the literature regarding 84% alcohol. So far,
the mixture is a dark grey to black with a little undissolved aluminium. There was a sudden exothermic reaction which occurred roughly 20 minutes
after mixture of Iodine, Al and EtOH and began to froth after some initial heating. This died down after 10 minutes as the literature suggested and
then continued to reflux for further 1.5 hours. Smells very ether-like but this of course is no certain indication of EtI. The additional water in the
mixture has changed the mixture grey rather than the deep red that anhydrous ethanol made it go before. Distillate is not very miscible with water. I
wonder, does the additional water create more Aluminium oxide/hydroxide? Following this reaction's results, I will attempt the Phosphorous acid KI
Ethanol reaction.
[Edited on 25-11-2017 by SamuelLFraction]
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Texium
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Threads Merged
26-11-2017 at 07:13 |
S.C. Wack
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The procedure above with the aluminum is sort of bullshit and should not be performed, because the scale was changed by the dickface who originally
posted this version that has been copied many times. The reactions may be rather too exothermic to proceed as written and deep unpleasantness beyond
low yield could result. Weights and volumes were originally 20x less, and a final weight was not given, but the words otherwise remain the same. You
want to test this on the smaller scale.
https://www.sciencemadness.org/whisper/viewthread.php?tid=65...
Both of these are short, thus are free to save as .gif from the RSC, until they change that
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SamuelLFraction
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Finishing the procedure calling for 84% alcohol has resulted in a cloudy distillate with a boiling point of 50-60. Bare in mind this distillate was
then further distilled once more and resulted the same end product. Immiscible with water, denser than water also. Aroma of sulphur/pickles, not very
pleasant. The procedure was followed exactly, however, resulted in everything but ethyl iodide. The product was immediately appropriately discarded.
Perhaps adding the H2SO4 and ethanol to the residue remaining from first distillation to then further distill had ruined this reaction entirely,
however, i am not going to attempt this reaction again to find out. Despite the 84% alcohol, iodine and aluminium method resulting in entire
disappointment, I have yet to test the suspected ethyl iodide produced (Silver Nitrate test) from anhydrous ethanol, of which is clear and denser
than water. Ether aroma present with this substance.
SLF
[Edited on 28-11-2017 by SamuelLFraction]
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Melgar
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The low yield in the reaction of iodine with aluminum and ethanol is because aluminum likes to keep some of the iodine for itself, and forms
combination hydroxide-iodide species, much like iron forms iron oxide-hydroxide species in the presence of water and oxygen. If you insist on doing
something more fun than H3PO4 + ethanol + iodide, you can always react iodine with elemental silicon to form SiI4, which will do just about anything
to swap those iodine atoms for oxygen atoms. It's 95% iodine by mass, and can be treated as though it were anhydrous HI for most practical purposes.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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SamuelLFraction
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Thank you Melgar, Silicon would most certainly be an interesting reagent to use. I'll be adding elemental silicon to my shopping list. I don't mind
the idea of using H3PO4, but as you quite rightly connotated, something more fun is... well, more fun 
Following on from reaction involving anhydrous ethanol with aluminium and iodine, the distillate was tested with a silver nitrate solution of ethanol,
water and NaOH and produced a yellow precipitate. At least the product is actually formed in this synthesis, so not entirely a waste of my time.
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JJay
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Nicoderm's procedure using HCl looks quite easy if you have reagent grade hydrochloric acid on hand. I wonder if potassium iodide would work as well
as sodium iodide.
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chemplayer...
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If someone wants to buy us a LC-MS for Christmas then hey, just tell us where to pick it up!
Seriously though, we don't try to produce scientific papers. We do it to learn and to have fun.
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arkoma
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AMEN!
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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Corrosive Joeseph
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| Quote: Originally posted by JJay | | Nicoderm's procedure using HCl looks quite easy if you have reagent grade hydrochloric acid on hand. I wonder if potassium iodide would work as well
as sodium iodide. |
Did I miss something........?
@JJay - Can you link me please
/CJ
[EDIT] - Pardon my laziness. 7 and a half seconds of UTFSEing yielded this -
"Iodomethane Via the HCl Method" - https://www.sciencemadness.org/whisper/viewthread.php?tid=23...
Excellent......... 
[Edited on 13-12-2017 by Corrosive Joeseph]
Being well adjusted to a sick society is no measure of one's mental health
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JJay
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I didn't have any luck getting it to work when I tried it a few months ago (and this was for methyl iodide, not ethyl iodide), but I'm not exactly
sure how strong my HCl was. I produced it by gassing azeotropic HCl with HCl gas until it appeared that very little was being dissolved. The amount of
iodine recovered after the experiment was far less than the amount of iodide that went into the experiment, so I think that a reaction happened, but I
didn't see an organic layer. I'm reluctant to believe that the methyl iodide simply escaped. My potassium iodide was granular, like table salt; it
could be that I should have used more finely powdered potassium iodide, but that doesn't explain what happened to the iodine.
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Surrealist
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Dissolve sodium iodide in acetone (399g/L, or 2.66 molar at 25 C) source: Pubchem.
Then bubble ethyl chloride through this to get the Finkelstein reaction, which is just an sn2 reaction driven by the insolubility of sodium chloride
in acetone. Organic chemistry portal has a good article on it: https://www.organic-chemistry.org/namedreactions/finkelstein...
As for making the ethyl chloride itself, a reactive distillation from ethanol and azeotropic hydrochloric acid should work well since ethyl chloride
boils at 12.3 C source: Pubchem. Be very careful and very patient with this setup and take very good care not to let any ignition source anywhere near
ethyl chloride. The ethyl chloride may not react immediately with the sodium iodide. Gentle heat to the acetone will accelerate the reaction, but can
be a safety risk. Use ethyl iodide in situ if possible. But that assumes acetone is a good solvent for your reaction.
My only experience in this reaction is the production alkyl iodides in situ to catalytically increase reaction rates, but I have never attempted to
purify one.
Please attempt this on a small scale and tinker before thinking of making a bunch of ethyl iodide. And read very carefully into the storage of ethyl
iodide.
I hope this helps.
[Edited on 28-7-2018 by Surrealist]
[Edited on 28-7-2018 by Surrealist]
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Chemi Pharma
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@Surrealist, your idea on how to make ethyl chloride will not work the way you are thinking. Ethyl chloride needs 99,8% ethyl alcohol, gaseous and dry
HCl and the most important: anhydrous zinc chloride. Without the last the acid won't react with the alcohol. The enviroment needs to be with the
minimum amount of water possible and the work up is to bubble HCl into a solution of anhydrous ZnCl2 in absolute alcohol, cleaning the ethyl chloride
gas first with a water wash to remove the HCl vapors and after with a H2SO4 wash bottle, to remove the umidity.
There's a synthesis of that in the book "Preparation of organic compounds, E. de. Barry Barnett, 71, 1912", published by Prepchem.com on the NET.
"To the round bottom flask fitted with properly cooled reflux condenser and gas inlet 100 g of ethyl alcohol and 50 g of anhydrous zinc chloride are
placed. The top of reflux condenser is connected to two washing bottles. The first has water and the second concentrated sulfuric acid. Finally
apparatus is connected to a cooled flask for condensing the reaction product. A dry stream of hydrogen chloride gas is passed through the boiling
mixture. The vapors of ethyl chloride is washed with water, concentrated sulfuric and condensed in a flask which is cooled with freezing mixture of
ice and salt. As ethyl chloride boils at 12° C it must be kept in sealed glass tubes. The yield is almost quantitative."
I think it's too much work to get ethyl iodide as the final target and I'd rather to use an easier method with KI + H3PO4 and ethyl alcohol I
discribed as an attachment, lines above, in my last manifestation on this thread.
[Edited on 28-7-2018 by Chemi Pharma]
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Surrealist
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I should have remembered the Lucas reagent/test. Thank you for pointing out my error Pharma. Maybe a setup like this could be useful in the case of
secondary alkyl iodides, but not primary since they won't react with the Lucas reagent (anhydrous zinc chloride and very concentrated hydrogen
chloride), and not tertiary since those don't undergo the Finkelstein reaction. But I'm getting ahead of myself since I don't have any projects that
need alkyl iodides currently.
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S.C. Wack
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Heating the Lucas converts primary alcohols so yes you can make the chloride that way, but if you're using ethanol, KI, and HCl for ethyl iodide maybe
the experiment can be more direct:
https://www.sciencemadness.org/whisper/viewthread.php?tid=12...
The 1857 date BTW is a few years after the author made large amounts of nitroglycerin, leaving imperfect directions for doing so.
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