Making my favorite liquid carcinogen

The sulfochromic mix was used more recently too (I was a graduate student in the US in the late 90s-early 2000s) but it did not go down the drain. :)

Silviu T

Speaking of Bromine. Mom was a clinical chemist, back in Greece, in the days long before automatic blood analyzers, when blood and other biological sample tests were done the hard way. For reasons that she could not remember, she had about a liter of bromine in her stock cabinet, but she never let me play with it. She did let me play with all sorts of other dangerous stuff when I was a teenager (always behind a fume hood, of course), including fuming nitric acid, metallic potassium, 55% H2O2, picric acid (we kept it at home; the aqueous solution is great for mild skin burns). Good times. In her lab, they routinely used what they called Chromosulfuric solution (K2Cr2O7 + H2SO4 + water as it got used) to clean glasswear from biological fluids, mostly blood. The stuff was stabler than piranha bath. This being Greece in the 60s and 70s, everything went down the drain of course. I had kilograms of K2Cr2O7 at home, I used it, among other things, as a bleaching solution to make black-nd-white transparencies. That also went down the drain. For the record, I have all ten of my fingers and both my eyes :)

John Ioannidis

Thanks for the comparison with Br. I was thinking about it since I saw your original video on CrO2Cl2. The limited color gamut of camera+youtube+monitor does not really show any color difference, I assume the contrast is starker when you have the stuff in front of you.

John Ioannidis

Kosher salt has no KI and no anticaking agents.

John Ioannidis

Can't wait to see the cleanup video!

Hey Red Nile have you tried distilling Antifreeze (Ethylene glycerol) with Siver nitrate and producing Glyceraldyde? The yield is like 30-40 percent.

Daniel Blake Shoemaker

I'm going to read Étard's original report, and will let you know if I find anything relevant. EDIT: Here it is. Étard dissolved separately toluene and chromyl chloride in cold carbon disulfide (10 % w/w solutions), but he states that chloroform works also (I suppose dichloromethane does too). Then he pours piecemeal the solution of chromyl chloride into the solution of toluene, with cooling to avoid the solvent boiling. That gives rise to a brown precipitate, which he purifies using vacuum filtration and an excess of CS₂. Now that brown precipitate reacts exothermically with water to give benzaldehyde. To purify benzaldehyde, the fraction is isolated in a separating funnel, then reacted with sodium bisulfite, with which it forms a precipitating adduct that can be purified by filtration/washing, then restored to its aldehyde form by adding sodium bicarbonate. On a different matter, the brown spots you get during the distillation might be chromium IV oxide, the magnetic oxide formerly used to coat recording tapes, which, as Wikipedia mentions, is obtained from decomposition of chromyl chloride (duh!). Maybe you should check if those brown spots are magnetic and insoluble in water. I think I had something else to add, but I can't remember right now.

Mono Keras

TBH, my experiment with bleach was made on the back of an envelope. I poured a few cl of a benzyl alcohol aqueous solution (unknown concentration, but probably saturated because there are blobs of pure benzyl alcohol at the bottom of the vial it is stored in) in a small plastic beaker, added a few drops of 4% NaClO bleach extract in it, stirred that, put it in a pan filled with water that I warmed a little, then I let it cool. It started giving off an almond scent like an hour later. That scent was quite persistant: I've done that experiment, like, a month ago, and it is just beginning to fade (admittedly I wrapped the small beaker in a plastic foil to avoid oxidation). It's not easy to guess a yield, but it's not negligible. However, I'm still wondering how to extract and purify benzaldehyde. There's very little data on it, and even the famous book "Purification of Laboratory Chemicals" doesn't have an entry for it. If you have any info, be my guest :)

Mono Keras

yeah it can be really bad sometimes :(

Nile Red

Hey Nile — it’s really impossible to type a reply in using this interface with a mobile. I’ll try later from a true computer. :(

Mono Keras

10 should be chlorine trifluoride... :D

Clifton Ballad

Thanks!

Nile Red

Ah okay, that makes a lot of sense. Thanks!

PseudsPie

You’d mentioned that you changed your process and I was just wondering about the details :)

Stephanie Guttormson

Sulfuric acid contains almost no water and its also super hygroscopic and loves holding onto water. This means that water made in the reaction can be sucked up by the sulfuric acid, instead of hydrolyzing some of the chromyl chloride that was just made! It helps increase the yield. Other acids with a lot of water, like HCl or HNO3 might also work, but it would cause a lot of the product to get hydrolyzed and lower the yield.

Nile Red

What do you mean? Compared to my original prep?

Nile Red

For the Etard, i did do it a long time ago, but i wasnt happy with the results so i took the video down. I want to do it again and only post it when I am happy with it. You're right though, there is very little info about it.

Nile Red

We you able to isolate a decent amount of benzaldehyde from that? Also, thanks! I appreciate it. I've been putting a lot more work into getting that crispy footage :).

Nile Red

My neighbors bodies are my filter (jk). I work in a commercial area and I do it late at night so no one is around. I really should set up some proper filters for stuff like this though.

Nile Red

Nice! But I hope you've got good filters on your fumehood and aren't just venting that in the neighborhood... ^^

Gabriel J.

Benzaldehyde is naturally found in bitter almonds, yes. I recently made some simply by mixing benzyl alcohol with bleach and heating a little. Works very well, gives out a strong pleasant fragrance of almonds, redolent of a brand of glue used by elementary school pupils over here ("Colle Cléopatre"). Starting with the nasty odour of bleach, this is definitely an improvement! :) So, I was hoping you might’ve have tried an alternative route to chromyl chloride, like the one we talked about and is described in Inorganic syntheses volume 2. I'm going to do that myself in about ten days – I have already whipped up the 36% hydrochloric acid (by bubbling HCl gas into commercial grade hydrochloric acid) – and I'm really curious to know if this "wet" method works, because it needs no distillation, just a separating funnel, apparently. Also yes, I'm looking forward to see if you succeed with the Étard reaction. I remember you posted a very short sequence in your first video about chromyl chloride in which you explained that was your setup for it. So it was a phoney? :p I searched a bit here and there, and did not manage to find any detailed procedure, except that chromyl chloride forms a complex (the "Étard complex") with toluene that must then be hydrolysed to get the benzaldehyde. I might read the original article from Étard in the Compte-Rendus de l'Académie des Sciences. In any case, a nice video. And yes, the solid crud you get might be chromic acid. It might explain also the tendency of chromyl chloride to expand on a watch glass: it might form a thin layer of chromic acid when it reacts with moisture in the air. Well done! Also, very clear and crisp pictures. You definitely have now hit your stride with shooting Hi-Q videos!

Mono Keras

Who wouldnt love that?

Nile Red

It is used in both cherry and almond, but I think its use as a cherry flavor/aroma is a lot more interesting. Using it as a cherry flavor is "artificial" but for almond, i guess it would be natural.

Nile Red

What changes to your process did you make? I’m super interested to know.

Stephanie Guttormson

It's actually used for both, but I think the cherry part is much more interesting than almond.

Nile Red

At 3:39, you mentioned that you used sulfuric acid and that you've done it before, but why specifically sulfuric acid?

PseudsPie

"I don't recommend you try this at home..." *whistles and hides the sulfuric acid*

Brian Reddeman

A nice video! Though it has a minuscule error: Benzaldehyde is what is used in almond essence. It's that fake almond aroma. But it's not that fake after all. The aroma comes from cyanogenic glucosides. Witch in the rose family [Rosaceae] are prunasine and amygdaline. The only differ between those two is that amygdaline has two glucose molecules bound in it, instead if the single one in prunasine. When the glucose is parted off, nitrile is left. Which is again split into benzaldehyde and hydrogen cyanide. Amygdaline is the chemical, that gives the bitter taste of apple seeds. But it's also in cherry pits and other many others. Cherry laurel [Prunus laurocerasus] also has a glucoside content in its fruit pulp. so it's equal to 100-200 ppm HCN (hydrogen cyanide). Apple seeds has ca. 300 ppm HCN. I guess the fruit pulp from cherries also have a minuscule amount of glucoside content, there by they use benzaldehyde in cherry aroma, but cherry aroma is much much more (as I think you already know). But it finally nice to get my chemistry craving satisfied again! ;-)

Alf-Marius Dahl Bysveen

"I love that it's dangerous explosive and looks like blood and gore" LOL

Arthur Wesley

Hi. I think benzaldehyde is almond flavor; not sure if it's also involved in cherry.

Cool.

Daniel Blake Shoemaker