Sciencemadness Discussion Board

Competition: Idoform (or iodoform even)

aga - 21-5-2018 at 12:54

I've googled and used the 'search' thing and can find no reference to Idoform synthesis on sciencemadness.org.

Akhil Jain (on utoob) pointed me at Shiva Chemist (also utoob) which is where i first saw this synthesis.

Wish i had found those guys 4 years back when i started with this Chemistry stuff - they do things and just have fun ! No big wordy stuff - they just Do stuff.

Anyway, there is no Prize, apart from being the First Amateur Chemist to post and detail their synthesis of Idoform on SM.

You'd be the First, ever.

Idoform used to be a standard disinfectant in hospitals so they say.

Method (it's said to be a very reliable haloform reaction):-

Any aldehyde, secondary alcohol or methyl ketone in Basic conditions, heat to around 60 C, add iodine.

End point is when the reaction mixture stops dissolving the brown Iodine colour and chunks of yellow precipitate form.

Filter, dry, you got old-time-hospital-smelling idoform.

Here's a video:-
https://www.youtube.com/watch?v=PPL-7M8rrNU

[Edited on 21-5-2018 by aga]

[Edited on 21-5-2018 by aga]

Micro scale prep

LearnedAmateur - 21-5-2018 at 13:15

0.01* moles is prepared from the following:
2.5g iodine
0.4g NaOH
0.6g isopropanol

2.5g iodine is added to 0.6g isopropanol.
0.4g NaOH is dissolved in 10mL water.
NaOH solution is added to isopropanol + iodine and swirled vigorously.
???
Chunky yellow precipitate forms, smelling of disinfectant.
Woo, iodoform!

*Not really, considering that the stoichiometry is completely wrong. More like 0.0025 mol via the equation iPrOH + 3 I2 + 4 NaOH. Originally, it was a 1:1:1 molar ratio because I decided to rush it and not think it through.
EAEB7AA3-7D28-4CD4-BFA5-0AA28871F380.jpeg - 163kB

[Edited on 22-5-2018 by LearnedAmateur]

MrHomeScientist - 21-5-2018 at 13:15

hkparker did it in 2011: https://www.youtube.com/watch?v=OARF9IIeHVA

He's an SM member, though he hasn't been around for a long time (off to college). Challenge complete! :D

clearly_not_atara - 21-5-2018 at 13:21

Is it possible that the issue is that you misspelled iodoform as "idoform"?

aga - 21-5-2018 at 13:26

Yep !

LearnedAmateur is a Winner !

... and he managed to spell it right too !

Edit:

Using the CORRECT spelling it has been discussed before, yet LearnedAmatueur takes the prize - photo documented ;)

More edit:

Bugger. Got to filter and dry it and photo the result.

[Edited on 21-5-2018 by aga]

aga - 21-5-2018 at 13:38

Quote: Originally posted by MrHomeScientist  
hkparker did it in 2011: ...

Doesn't count - wasn't on SM.

Ditto Georges-Simon Serullas in 1822 - wasn't photo-documented on SM.

No excuse that neither SM nor the Internet existed back then - he had the opportunity to invent both and take the accolade.

[Edited on 21-5-2018 by aga]

LearnedAmateur - 21-5-2018 at 13:39

Ugh, but that’s effort. Nah, I won’t take the ‘prize’ because it’s quite easy to make, just wanted to do it for the sake of chemistry plus I have to get to bed now so I don’t have the time to work it up. All I had to do was throw all the reagents into one pot, the heat of dissolution from the NaOH was enough to bring it all to reaction. The red iodine solution, when dribbled into NaOH solution immediately lost its colour - now that’s the cool part of this, I find.

1478BD4B-A3E6-426E-ADB3-790D810EFB3A.jpeg - 511kB

aga - 21-5-2018 at 13:42

Filter paper, funnel, tip vial into funnel, go to bed.

Oh the Effort !

You'll still be 100km ahead of the competition when you wake up.

LearnedAmateur - 21-5-2018 at 13:53

Well I’ve added some more reagents to bulk up the iodoform, just eyeballed until the iodine stopped dissolving. I’ll filter some out and present the results in the morning, might have a go at recrystallising some tomorrow.

aga - 21-5-2018 at 13:55

If you do, i'll have a go at recrystallising mine in 95% ethanol and share the results.

LearnedAmateur - 21-5-2018 at 14:03

I’ll try with isopropanol, apparently ethanol is at 78g/L and acetone with 120g/L @RT so I’m estimating it’ll be hovering around the 100 mark for my choice. I’ll only have a couple grams at most filtering through so I shouldn’t need more than 20-30mL at elevated temperatures. Actually kind of excited to see how they turn out, only ever precipitated it before (not including today).

DavidJR - 21-5-2018 at 15:04

Quote: Originally posted by aga  
If you do, i'll have a go at recrystallising mine in 95% ethanol and share the results.


I had real trouble recrystallising from acetone.

Texium (zts16) - 21-5-2018 at 15:09

I made iodoform two years ago and found that it decomposes in acetone, but I was able to boil off the acetone, and wash the resulting sludge with sodium metabisulfite solution, and that fixed it right up. Ethanol, isopropanol, chloroform, or DCM, would be better. Really, acetone is a crappy solvent. I never recrystallize anything from it anymore.

https://www.sciencemadness.org/whisper/viewthread.php?tid=64...

And here's my iodoform, weighing in at 4.46 grams:

IMG_4442.JPG - 1.4MB

The picture still doesn't do the brilliant lemon yellow color justice. Unfortunately I made that back in the wild-west days, before I kept a regular lab notebook for all of my experiments (it would have been just before I started). So I don't remember exactly what procedure I used or what my yield was, though it's a pretty good chunk, and I don't have any use for it, so I don't see myself making any more.

[Edited on 5-21-2018 by Texium (zts16)]

DavidJR - 21-5-2018 at 15:23

Quote: Originally posted by Texium (zts16)  
I made iodoform two years ago and found that it decomposes in acetone, but I was able to boil off the acetone, and wash the resulting sludge with sodium metabisulfite solution, and that fixed it right up. Ethanol, isopropanol, chloroform, or DCM, would be better. Really, acetone is a crappy solvent. I never recrystallize anything from it anymore.

https://www.sciencemadness.org/whisper/viewthread.php?tid=64...

And here's my iodoform, weighing in at 4.46 grams:



The picture still doesn't do the brilliant lemon yellow color justice. Unfortunately I made that back in the wild-west days, before I kept a regular lab notebook for all of my experiments (it would have been just before I started). So I don't remember exactly what procedure I used or what my yield was, though it's a pretty good chunk, and I don't have any use for it, so I don't see myself making any more.

[Edited on 5-21-2018 by Texium (zts16)]



Yeah, I rarely use acetone at all to be honest, I only had it out since I decided to use it as the substrate instead of isopropanol (which would just be oxidised to acetone anyway).

I suspect recrystallising from isopropanol would work much better, but I haven't tried it.

Texium (zts16) - 21-5-2018 at 15:30

Also see this thread: https://www.sciencemadness.org/whisper/viewthread.php?tid=16...

Looks like woelen already posted a beautiful picture of iodoform crystals dry, in a vial, in 2011, along with the procedure he used to make it. By your criteria, aga, he would take first prize. mewrox99 and Mailinmypocket ALSO posted pictures of dried iodoform. So that makes at least 4 of us already, aga :P

Having correct spelling goes along with UTFSE!

LearnedAmateur - 21-5-2018 at 21:54

Well mine are still filtering despite being left overnight, looks like I won’t be sharing any contributions this morning. Was hoping for some relatively dry precipitate but the funnel is still half full with supernatant liquor - maybe later on it’ll be done.

aga - 22-5-2018 at 05:47

Quote: Originally posted by Texium (zts16)  
... that makes at least 4 of us already, aga :P ...

Doh !

Ah well. It was a bit of fun.

Edit:

All started going downhill somewhere just before the start.
Just dissolving the stuff in 95% ethanol isn't going well !

idiotoform.jpg - 42kB

[Edited on 22-5-2018 by aga]

Tsjerk - 22-5-2018 at 12:43

It looks you dissolved some impurities out of your product though, not completely useless.

aga - 22-5-2018 at 12:46

Needs a bigger pot, and i really can't imagine adding more of that 95% ethanol.

Well, i can imagine it, but the image is terrifying !

Edit:

A mildly interesting find was the "MINIMUM STANDARDS OF OPERATION FOR MISSISSIPPI HOSPITALS" document (attached).

Page 58 - Iodoform is regarded as 5x as effective as bleach or phenol for killing off pathogens, 4x as effective as a 'Quaternary ammonium solution' whatever that is.

Attachment: 7419.pdf (1.1MB)
This file has been downloaded 111 times

[Edited on 22-5-2018 by aga]

DavidJR - 22-5-2018 at 13:03

Other than as an antiseptic/disinfectant (and smelling quite nice) is iodoform particularly useful for anything?

aga - 22-5-2018 at 13:07

Weird question.

What has Iodoform ever done for us ?

https://youtu.be/Qc7HmhrgTuQ?t=11

DavidJR - 22-5-2018 at 13:23

Quote: Originally posted by aga  
Weird question.

What has Iodoform ever done for us ?

https://youtu.be/Qc7HmhrgTuQ?t=11


Well, chloroform and bromoform are both potentially useful as solvents at least.

mayko - 22-5-2018 at 14:12

It's used in the Takai olefination... though word on the street is, that reaction is generally more trouble than it's worth:

https://en.wikipedia.org/wiki/Takai_olefination

AJKOER - 22-5-2018 at 19:39

Quote: Originally posted by aga  
....

A mildly interesting find was the "MINIMUM STANDARDS OF OPERATION FOR MISSISSIPPI HOSPITALS" document (attached).

Page 58 - Iodoform is regarded as 5x as effective as bleach or phenol for killing off pathogens, 4x as effective as a 'Quaternary ammonium solution' whatever that is.

[Edited on 22-5-2018 by aga]


Importantly, weakly acidified bleach, which forms hypochlorous acid, is claimed to be about 120 times stronger than bleach (see https://www.aquavertclean.com/what-is-hypochlorous-acid-and-... )!

HOCl has been suggested as a wound treatment (see https://www.ncbi.nlm.nih.gov/pubmed/25785777), where, I suspect, iron rich blood reacts with the hypochlorous acid in a fenton-type reaction forming the powerful disinfecting hydroxyl radical.

However, unlike stable iodoform, ordinary HOCl usually has a short shelf life.

[Edited on 23-5-2018 by AJKOER]

Texium (zts16) - 22-5-2018 at 20:29

OMG can you post about ANYTHING other than HOCl?

Or tollens?

Vomaturge - 22-5-2018 at 21:02

Quote: Originally posted by clearly_not_atara  
Is it possible that the issue is that you misspelled iodoform as "idoform"?


That is an easy one to misspell, but it makes little difference. It's not like the difference between DIIodomethane/DIIdomethane and DIldomethane:D

Edited to contain some real comments on the thread, instead of just the spelling of "iodo" compounds.

Seriously, though, this looks like a cool reaction. I need to find out a little more about the haloform reaction, but I kind of understand the basic principles. The methyl group on the ketone/alcohol gets oxidized on three sides, and kicked off due to other reactions with the C=O part of the ketone. I still have more to learn about this.

Iodoform also sounds less toxic than chloroform. In order to actually make it though, I'd first need to determine the concentration of my NaOH&KOH drain cleaner, and then get some iodine (or else get the ingredients to isolate it from a bunch of povidone iodine. But those are all things I should do anyhow, so I might do this reaction eventually. Good job, everyone!

[Edited on 23-5-2018 by Vomaturge]

[Edited on 23-5-2018 by Vomaturge]

j_sum1 - 22-5-2018 at 21:14

What the hell is dildomethane??
Nah. Let's not go there.

DavidJR - 23-5-2018 at 01:52

Quote: Originally posted by j_sum1  
What the hell is dildomethane??
Nah. Let's not go there.


Flatulence while using a dildo?

mayko - 23-5-2018 at 07:23

I can't believe no one's mentioned QuantumCore's innovative approach:

https://www.sciencemadness.org/whisper/viewthread.php?tid=62...

Boffis - 25-5-2018 at 01:07

On the subject of dildomethane, I think there would be more of a competition in the reduction of iodoform to diiodomethane without using sodium arsenite, which is tricky stuff to get ones hands on.

As to QuantumCore's method the lack of quantitative detail makes the procedure difficult repeat and the results difficult to reproduce.