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DBL%20Hendrix%20small.png College chemistry, 1983

Derek Lowe The 2002 Model

Dbl%20new%20portrait%20B%26W.png After 10 years of blogging. . .

Derek Lowe, an Arkansan by birth, got his BA from Hendrix College and his PhD in organic chemistry from Duke before spending time in Germany on a Humboldt Fellowship on his post-doc. He's worked for several major pharmaceutical companies since 1989 on drug discovery projects against schizophrenia, Alzheimer's, diabetes, osteoporosis and other diseases. To contact Derek email him directly: derekb.lowe@gmail.com Twitter: Dereklowe

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May 15, 2012

Things I Won't Work With: Selenophenol

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Posted by Derek

This fine reagent was mentioned here (disparagingly) in the comments the other day, and I knew that it was time to add it to the list. I've had some other selenium entries before, and they're all here for the same reason: their unsupportable stenches. Everyone, even people who've never had a chemistry class in their lives, knows that sulfur compounds are stinky, of course, but it's a problem that continues as you move down Group XVI of the periodic table.

And it's not like plain phenol itself has no odor. It's strong, penetrating, and completely unmistakable. As soon as I get a whiff of the stuff, I'm immediately transported back to the Verser Clinic, the small hospital in the town I grew up in back in Arkansas. Phenol smells like an old-fashioned medical office; it was used for many years as a disinfectant (and was, in fact, introduced as such by Joseph Lister himself). If you move it down a notch to sulfur, you get thiophenol, which is easy to describe: burning rubber - the pure, potent, platonic ideal of burning rubber, bottled up and daring you to open the cap. I can't say that I won't work with thiophenol, since I have (very much to my regret, at times), but I've used it most reluctantly, and probably haven't touched it in at least fifteen years.

Ah, but move down one more element and you have selenophenol, and that's a more exotic reagent. I've never seen any, and after reading the descriptions, I never want to. Actually, let me take that back: I'd look at some from the other end of the lab. What I never want to do is open any of it up. The chemical literature has numerous examples of people who are at a loss for words when it comes to describing its smell, but their attempts are eloquent all the same. A few years ago, Gaussling at the Lamentations on Chemistry blog referred to it as "The biggest stinker I have run across. . .Imagine 6 skunks wrapped in rubber innertubes and the whole thing is set ablaze. That might approach the metaphysical stench of this material." So we'll start with that.

I believe that this lovely compound is commercially available (if you're anywhere close to anyone making it, you'll know about it). But should you wish to prepare it with your own hands, do violence to your own schnozz, and drape yourself out of your own window while you throw up into your own rhododendrons, feel free to use this reliable preparation from Organic Syntheses, circa 1944. This features the note that "it is frequently advisable to work with [selenium compounds] on alternate days", which I suppose is to give them time to work their way out of your nasal passages.

I'm not so sure. When I was a teaching assistant in grad school, I taught three labs a week one semester, and one of those labs, damn it all, was the phenyl Grignard reagent. We had them making it in diethyl ether, outside of the small and inadequate fume hoods, and the solvent fumes were fit to strip paint. By the end of the Monday lab, I was well saturated with ether and had a terrible headache, which returned as soon as I caught my first whiff of the stuff on Tuesday afternoon. I barely made it through that lab, mostly by holding my breath and using a lot of hand gestures, and I took the opportunity on Wednesday to get as much fresh air as I could. But when I came back for the Thursday session, the first first wave of ether vapor washed over me and nearly stretched me out on the tiles. I taught the entire lab from the hallway, shouting and waving like Monty Python's "Semaphore Version of Wuthering Heights". So in my mind, the choice between getting these things over with and stretching them out is still not settled.

That Org Syn prep also notes that it can produce small amounts of hydrogen selenide, which is very toxic indeed (and will give you a sore throat, too, apparently, before it kills you). This luckless graduate student from the 1920s got to experience both of these bracing selenium room fresheners in the course of his work:

Berzelius described the poisonous effect of hydrogen selenide quite impressively; "In order ta get acquainted with the smell of this gas I allowed a bubble not larger than a pea to pass into my nostril ; in consequence of its smell I so completely loss my sense of smell for several hours that I could not distinguish the odor of strong ammonia even when held under my nose. My sense of smell returned after five or six hours, but severe irritation of the mucous membrane set in and persisted for a fortnight' The writer has been working on the gas for some time and was also quite seriously affected once, the injury persisting for many days. That it is more poisonous than the hydrogen sulphide is well known."

So you have that to look forward to on your way to selenophenol. And at your destination? Assuming your nose is still attached to your face, you'll experience what few chemists ever have. I'll let this 1908 report from Wisconsin take over:

When benzeneselenonic acid in solution is treated with reducing agents such as hydrogen sulphide, sulphur dioxide, or, best, with zinc and hydrochloric, acid selenophenol is obtained as a yellow oil with an overpowering and most nauseating odor. . .The odor of diphenyl diselenide is extremely disagreeable but is not nearly so bad as that of selenophenol.

. . .The effect of selenophenol on the skin is very similar to that of thiophenol, forming blisters which itch intensely. After a time, these dry up, the skin scales off, and there appears to be a deposit of red selenium beneath it. The odor of selenophenol is very penetrating, and is nauseating beyond description.

Gloves, man, gloves. Unless, of course, you wish to be tattooed with elemental selenium while being nauseated beyond description. Should this be your idea of a fun Saturday night, I will not stand in your way.

Comments (47) + TrackBacks (0) | Category: Things I Won't Work With


COMMENTS

1. petros on May 15, 2012 8:26 AM writes...

At least one selenium containing drug has been evaluated extensively in the clinic

Ebselen
http://en.wikipedia.org/wiki/Ebselen

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2. Nekekami on May 15, 2012 8:44 AM writes...

Question from a non-chemist:

I read through the preparation you linked, Derek, and saw the mention of n-butylselenol. Given the reactions you chemists seem to have when n-buli and t-buli are involved, I was wondering if the n-butylselenol was anywhere near as horrible.

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3. Curious Wavefunction on May 15, 2012 9:02 AM writes...

Has anyone ever made and smelt Tellurophenol? I cannot help but reproduce the exchange Pauling had with Matt Meselson about H2Te:

Linus Pauling: Well, Matt, you know about tellurium, the group VI element below selenium in the periodic chart of the elements?

Matthew Meselson Uh, yes. Sulfur, selenium, tellurium . . .

Linus Pauling: I know that you know how bad hydrogen sulfide smells. Have you ever smelled hydrogen selenide?

Matthew Meselson No, I never have.

Linus Pauling: Well, it smells much worse than hydrogen sulfide.

Matthew Meselson I see.

Linus Pauling: Now, Matt, hydrogen telluride smells as much worse than hydrogen selenide as hydrogen selenide does compared to hydrogen sulfide.

Matthew Meselson Ah.

Linus Pauling: In fact, Matt, some chemists were not careful when working with tellurium compounds, and they acquired a condition known as "tellurium breath." As a result, they have become isolated from society. Some have even committed suicide.

Matthew Meselson Oh.

Linus Pauling: But Matt, I'm sure that you would be careful. Why don't you think it over and let me know if you would like to work on the structure of some tellurium compounds?

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4. RB Woodweird on May 15, 2012 9:21 AM writes...

Great Fieser's Ghost! I would not describe the effect of selenophenol on the human body as a smell but as a state of mind. It is a hypnotic effluvia which beams its essence straight to the area postrema. It should be packaged as a gold standard, triple-your-money-back, Jenny-Craig-bankrupting weight loss device.

That said, PhSeNa and PhSeCl are such darn good reagents that I put up with a little violent bilious retching now and again.

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5. El Selectride on May 15, 2012 9:37 AM writes...

That little bit generated from quenching excess PhSe- never really bothered me. Of course I pulled the flask out of the hood to have a quick waft. Just plain old burning rubber. Nothing special. I'm not sure it's volatile enough to get that full nostril-burning, lab-clearing effect of a true TIWWW, but if you spill some on yourself...

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6. Former Merck Chemist on May 15, 2012 9:41 AM writes...

....Gloves, man, gloves... Excellent :)!

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7. A Nonny Mouse on May 15, 2012 9:50 AM writes...

I used to make it in situ from diphenyl diselenide; no problems at all as the sodium salt.

The worst problem was with the diselenide which we had purchased from Aldrich as it contained red selenium which did stink. I dissolved the lot up in DCM, filtered and shipped the red stuff back to Aldrich as I had not ordered it.

They rejected their entire stock and sent it to us. It kept the lab going for quite some time.

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8. MikeEast on May 15, 2012 10:06 AM writes...

Personally, I'll take the smell of PhSeSePh (presumably with a little PhSeH) or PhSeBr over a mercaptan any day of the week and twice on Sunday. Benzyl mercaptan is the worst.

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9. John Li on May 15, 2012 10:15 AM writes...

I have been using PhSeBr recently and it doesn't stink at all, although i didn't put my nose in inside the bottle and sniff it...

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10. David Formerly Known as a Chemist on May 15, 2012 10:22 AM writes...

I never found selenides to smell as bad as sulfides, just...different. Sulfides have that rotten skunky stench. The only way I've ever been able to describe the selenide smell to my own satisfaction is with words like "chemically, repugnant metallic". I can't think of anything a non-chemist would have experienced in nature that's anything close to a selenide. It's just a bad metallic stink.

Back in grad school we used to joke about using a syringe to squirt a good 50 cc of this stuff (or thiophenol) into an enemy's car through the rubber window seal. Can you imagine opening your car door in the morning after someone did that? Blech!

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11. Dave on May 15, 2012 10:23 AM writes...

Electronic technicians of the 1950s and 1960s were quite familiar with the stench of Selenium compounds. Many pieces of electronic equipment from that era used Selenium rectifiers, and these would occasionally fail, and spew burning Selenium (mixed with various heavy metals, used to form a low temperature solder, such as Cadmium, etc.). And, to think that these things were installed in customer's homes! Eeeek!

Dave

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12. Kevin on May 15, 2012 10:42 AM writes...

Indeed, PhSeH has nothing on Benzyl mercaptan. In grad school we referred to the latter as fermented-cajun-skunk-turd-on-fire.

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13. milkshaken on May 15, 2012 10:45 AM writes...

On the other hand, for those inclined to reduce nitrostyrenes to substituted phenethylamines in their own garage lab and would rather avoid using LAH in anh THF, (like in PIKAL), the good news is that borohydride in alcohol works fine for the purpose, provided that few mol% of metallic selenium is added at later point - the in situ generated NaSeH takes nitro to amino, H2Se at the end gets oxidized by air during the workup to red Se and crashes out...

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14. Biotechtranslated on May 15, 2012 11:36 AM writes...

I've never found Ph2Se2 to have all that bad of a smell. I think one of the major sources of the bad smells are small quantities of impurities, usually ones that have selenol functional groups.

The worst smell I ever came across was during a selenium reaction (free radical selenosulfonation). The solvent had boiled off and the reagents were a black goo at the bottom of the flask. Wow did that ever smell bad. A combination of garlic, burnt rubber and skunk. Enough to kick your brain into a fight-or-flight response.

Mike

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15. Simon on May 15, 2012 11:52 AM writes...

I was a PhD student in a group that investigated selenoethers and (thank God, after I had left) telluroethers as ligands. Luckily my project 'only' involved phosphines, arsines and stibines. However, a contemporary of mine had a great deal of trouble finding himself a squash partner. Once he was warmed up, out came the organoselenium compounds in his sweat. He couldn't even tell!

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16. Mike on May 15, 2012 12:40 PM writes...

I had the opportunity to work with both thiophenol and selenophenol. To my nose, selenophenol was not really any worse than thiophenol. And it was in fact easier to contain in the fume hood - presumably due to its lower volatility. So, Derek, if you're able to withstand working with thiophenol, then you can handle selenophenol.

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17. luysii on May 15, 2012 1:07 PM writes...

Not that thiols are perfumes. I had to work with aliphatic thiols for my senior thesis (nBu-SH, etc. etc.) primarily to study their hydrogen bonding, in order to look at things like Phe-(CH2)n - SH for hydrogen bonding to the pi electron cloud of Phe (remember this was over 50+ years ago). When I'd walk into the dining room of my eating club, people would start looking at their shoes.

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18. Kornchemist on May 15, 2012 1:52 PM writes...

As someone who works extensively with both thiophenol (on the multiple gram scale) and elemantal selenium (with the occasional diphenyl diselenide thrown in there for good measure, I find that the smells actually grow on you. Thiophenol smelled foul about the first 3 times and now I'm pretty much desensitized, to the point that if i have drop-size quantities on my gloves I'll hardly be bothered by it. Just give it some time boys, it'll not be nearly as bad after a couple times. (Then again, I smell DMS and i think cabbage/hungry. I think my olfactory nerves may be a little crossed but oh well...)

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19. gippgig on May 15, 2012 1:58 PM writes...

#3: There's always polonophenol, and now livermorophenol (hmmm, do you really want to have a chalcogen named after you?).
It is interesting to note that selenocysteine is the 21st amino acid - a rather weird story; in the genetic code UGA usually means stop but in a few special cases it is translated as selenocysteine. (Selenocysteine probably has little odor since it is a zwitterion and therefore should have zero volatility.)
How about including photos of the TIWWW?
On the other hand, how about Things I Love to Work With?

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20. Chad on May 15, 2012 1:59 PM writes...

I worked on thiols as a grad student and while thiophenol was horrific, thioacetic acid was far worse. It is easily the foulest shit I've ever come across. I'm sure I stank terribly that year.

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21. John Wayne on May 15, 2012 2:23 PM writes...

Organoselenium smells like a robot farted.

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22. sigh on May 15, 2012 2:44 PM writes...

and people wonder why the life expectancies of chemists have improved . . .

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23. vanad on May 15, 2012 2:45 PM writes...

I have worked with PhSeH a fair bit, also PhSH, PhSeSePh and various other Se derivs.
The big advantage of PhSeH over PhSH smellwise is that it is so easily oxidised in air to PhSeSePh (which is completely odourless and for example is inconsequentially recrystallisable on the open bench -- of course it may indeed be supplied containing smelly impurities), so by introduction of air after completion of the reaction, glassware contamination by smelly derivatives is trivially kept to nil. The redox status of selenol(ate) to diselenide interconversion is also easily monitored visually by a colourless to yellow colour-change.
For reactions requiring PhSe- nucleophile, where there is a choice between using PhSeH or PhSeSePh/NaBH4, price (PhSeH is more expensive) or a preference for weighing out solid reagents could be significant factors in deciding which method to choose.

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24. Flatland on May 15, 2012 3:38 PM writes...

Derek,

You forgot the best part of the Org Syn prep:
13. It is well to have a hot sulfuric-nitric acid cleaning bath in the same hood, so that apparatus need not be handled in the open laboratory. The large separatory funnel is conveniently cleaned by pouring into it 50 ml. of concentrated nitric acid. After a few minutes, the acid reacts violently with selenides remaining on the sides. The oxides of nitrogen produced effectively clean the funnel, which can then be rinsed with water.
14. Water-soluble selenium compounds are poured down the sink in the hood and flushed with much water. Rubber stoppers and gloves can be freed from toxic compounds by soaking them for a few minutes in bromine or chlorine water and then in dilute sodium hydroxide solution.

Fun Stuff

Talk of this has caused me to experience some nostalgia, so I figured Id share my $0.02. Ive never smelled selenophenol, but I am intimately acquainted with the smell of thiophenol, along with ethane, propane, and butane dithiol, from undergrad (making As and Hg ligands). I can say this with full confidence and certainty: thiophenol pales in comparison to the alkane dithiols. They stink, don't stop stinking, and the smell sticks to you for weeks (double the sulfur, double the fun). In undergrad, all it took was opening a bottle in a fume hood, and we would start getting phonecalls from other labs. Angry phonecalls. Someone once spilled a couple of mL in a hood in our lab once, and the police showed up because someone reported it as a chemical warfare attack. Ah, the good old days.

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25. barry on May 15, 2012 3:49 PM writes...

going on thirty years ago, a labmate tried the very small-scale reduction of a bromo-cyclopropane with H2Te. We were barely disappointed that it didn't work--no one wanted to repeat the experiment. The god-awful smell lingers in my memory if not in my nostrils to this day.

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26. Heisenberg on May 15, 2012 5:27 PM writes...

#13. Do you have a reference for that prep?

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27. My friend selenol on May 15, 2012 7:24 PM writes...

You folks are over the top. 30+ years ago I used to regularly make 100gm batches of PhSeH from that Grignard. It was easy and easy to keep fully contained. Liquid N2 trap on the rotavap, bleach etc. The rest was all about handling on a vac line in Shlenk tubes. It distills easily and was *way* *way* cheaper than ordering from Aldrich.

And, it was slightly different from PhSH but really not worse.

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28. Secondaire on May 15, 2012 8:11 PM writes...

#2 - no, generally, the problem with organometallics come from the carbanion character of the things, which are very very reactive (due to their instability). Something like t-butylselenol would probably be like t-butanol or t-butylthiol and not pyrophoric at all. Maybe smelly, though.

Man, a good portion of my post-doc involved thiol chemistry. A whole corner of the lab was permanently skunked out from the various thiophenols. I've experienced most of them and I could probably identify a few of them by odor. Thioanisole (used to use it as a cation scagenger) was almost worse than thiophenol, though because the stench hung around FOREVER. Ye Gods.

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29. Secondaire on May 15, 2012 8:19 PM writes...

#2 - no, generally, the problem with organometallics come from the carbanion character of the things, which are very very reactive (due to their instability). Something like t-butylselenol would probably be like t-butanol or t-butylthiol and not pyrophoric at all. Maybe smelly, though.

Man, a good portion of my post-doc involved thiol chemistry. A whole corner of the lab was permanently skunked out from the various thiophenols. I've experienced most of them and I could probably identify a few of them by odor. Thioanisole (used to use it as a cation scagenger) was almost worse than thiophenol, though because the stench hung around FOREVER. Ye Gods.

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30. milkshake on May 15, 2012 8:42 PM writes...

@26 no, you have to take my word for it. Use of borohydride with catalytic Se was a method I found, and it worked well for solid-phase suported nitro reductions - it was an inspiration from nitro reductions with sulphide as a reducing agent that can be catalyzed with addition of Se powder. I suppose once the conjugate reduction takes place that transforms nitrostyrene to nitrophenylethane with borohydride you can add few mol % of Se and finish the job. It needs mild heating to about 40-50C so the best solvent is EtOH or glyme for NaBH4 and THF for LiBH4

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31. Anonymous BMS Researcher on May 15, 2012 9:53 PM writes...

My PhD is in biology, not chemistry, so the nastiest smells I encountered in grad school were fairly tame stuff: rotting organic matter, ordinary animal execretions, formalin, insect defensive chemicals, and the like. Selenophenols and thiophenols are amusing to read about, but probably less amusing to smell. It's no wonder on the many college campuses I've known the Chem building always seems to have a special aroma.

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32. Anonymous BMS Researcher on May 15, 2012 9:54 PM writes...

My PhD is in biology, not chemistry, so the nastiest smells I encountered in grad school were fairly tame stuff: rotting organic matter, ordinary animal execretions, formalin, insect defensive chemicals, and the like. Selenophenols and thiophenols are amusing to read about, but probably less amusing to smell. It's no wonder on the many college campuses I've known the Chem building always seems to have a special aroma.

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33. Felix on May 15, 2012 11:52 PM writes...

I use the orgsyn prep to make the PhSeH regularly. It works well, but even with careful precautions, it's hard not to come out smelling skunky. Getting a good whiff of this stuff immediately causes discomfort and a headache, something thiophenol does not do. Any residual amounts easily oxidize overnight, making cleanup easier to perform the next day. I agree that it can be contained with a careful setup, but once you have to actually use it in the next reaction...well just hope it is a quantitative reaction with a really convenient work up.

I have not observed any red spots while using nitrile gloves and a lab coat.

I still agree with the title of the post, if you can, just don't work with this stuff. Life is already too short. Plus, no one appreciates a stinky chemist. Though by all means surprise your boss with your smelly self, they will be glad they are paying you to do this!

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34. RB Woodweird on May 16, 2012 6:29 AM writes...

The comments here and a recent discussion with a person who cannot stand the smell or taste of fresh tomatoes makes me recall that there is a certain percentage of the population which perceives things differently than the majority. Probably a genetic thing. Some people cannot stand the taste of cilantro, some like the smell of skunk.

The intersection of that with practical lab matters happens when one is working with cyanide. There is a fairly large percentage of the population which can't smell the stuff. Fortunately, I have a sensitive nose for it, so when I work with it I tell people that if they see me running they should try to keep up.

The alkyl thiol comments recall the time in the '80s when a biology student on the main campus at Boston U. was cleaning out their lab and poured a liter or so of butanethiol down the drain. At the time, the septic and storm drains were not separated, so the odor spread down the system from Commm Ave to the Fens to the Charles River. Boston Gas was innundated with frantic calls for miles around that there was a major natural gas leak in progress.

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35. GladToMoveToProcess on May 16, 2012 11:56 AM writes...

Yum! Where to start?

In grad school, I developed a sensitivity to thiophenol. A few mg spilled in the adjoining lab led to a splitting headache. Fortunately, this went away, and I can now work with it without problems.

Selenophenol: an undergrad of mine was making some Ph2Se2 over the weekend. Evidently, he wasn't all that careful: he broke into the emergency medical oxygen supply we kept in the lab in case of cyanide incidents, and told me it was the only way he could keep working.

@34. The cyanide anosmia is quite common, near 30% of the population. We used a LOT of it in my academic lab, and had compounds that could decompose explosively to give lots of HCN. So, the first thing with each new student was to see if they could smell HCN. A lot couldn't.

My own anosmia is for skatole (!!). My wife brought some home, in a sealed capillary inside a Teflon ziploc bag, inside two or three Mylar zip bags. I took it outside, opened it, and sniffed: nothing. Deeper sniff; nothing. Stuck my nose in the bag; eyes started watering, but still no odor. I was invited to stay outside for the next hour.

And the time I opened a bottle of tert-butyl mercaptan in the large lecture class I was teaching (I knew how the air currents moved in the room, and felt safe). It got into the air handling for the building, and I had to run around to all the offices explaining that it wasn't a gas leak. The dept chairman suggested that continued employment depended on not doing that demo again.

And a large prep in our kilo lab, which generated methyl mercaptan, dimethyl sulfide, and some low MW polyamines. The chemist doing the work came into my office and said "Daddy, take me to the circus - this stuff smells like elephant s**t!"

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36. metallabenzene on May 16, 2012 2:08 PM writes...

I actually don't think selenophenol is as bad as thiophenol (and I've worked extensively with both, I've even run that 1944 Org Syn prep on numerous occassions...). I find that selenophenol oxidized so quickly in air to diphenyl diselenide that its effective vapor pressure seems to be much reduced. That, or perhaps my nose just ain't that great!

That said, if you need PhSe anion, I highly suggest making it from lithium metal and PhSeSePh with sonication, or NaBH4 and PhSeSePh. Both methods allow you to avoid the dreaded PhSeH.

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37. exNVS on May 16, 2012 3:45 PM writes...

Brings back memories. As a postdoc (ca. 1975 or so) I made the stuff using the Org Syn prep. Used it to make diphenyl diselenide, from which I then made PhSeBr. I recall it being unpleasant, but not as bad as benzyl mercptan.

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38. DJN on May 16, 2012 6:25 PM writes...

In my long ago youth, I worked with phosphines and a variety of selenides in an organometallic chemistry group, then progressed to growing sulfate reducing bacteria on 400 litre scales. However, none of these made people give me a wide berth on the London Tube system, but a reaction of dimsyl sodium with an aryl epoxide certainly did. I could not smell it, but clothes had to be burned according to me then girl friend! DJN

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39. Pau Amma on May 22, 2012 6:30 AM writes...

Let's have a show of limbs: who else read this and was reminded of The Magnificent Possession?

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40. Torquill on May 28, 2012 2:01 PM writes...

Derek, as someone who got severely injured by fumes of ethylene glycol butyl ether (Formula 409, anyone?) and who still can't detoxify anything with "ether" in its name 12 years later, I am unsurprised that you were barely able to teach that lab class after three unprotected days in that atmosphere. Even straight ethers can do a number on your nervous system, and there's only so much abuse one's liver can take...

When I worked with diethyl ether in undergrad OChem, fortunately for only one step of two different reactions during the year, I used a VOC-class respirator and handed the job of monitoring distillation to the prof. She was sympathetic. I don't think we used sulfur compounds at all, it being a community college lab; I suspect they might have been involved when the prof had written on one of the experiments in the lab manual "Do not do! STINKS!!!"

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41. John Dallman on June 13, 2012 4:53 AM writes...

I woke up out of a sound sleep this morning remembering this post, and feeling glad that nobody seems to deliberately research or synthesise horrible-smelling compounds. The thought of what one could do by tacking a few seleniums onto already-foul compounds is ... worrying.

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42. David Marjanović on July 29, 2012 4:59 PM writes...

I can't think of anything a non-chemist would have experienced in nature that's anything close to a selenide.

I've seen the smell of H2Se explained as "rotting radish".

Haven't experienced either, though.

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43. Sampo Syreeni on September 27, 2012 9:08 PM writes...

Dimethylmercury. That's pretty much what you don't want to work with. It's much worse than even botulinum toxin and the ilk. Just read through the Wikipedia articles and you'll know; it kills the best of them, half a year afterwards, in the microgram doses which seep through your protective gloves...

*That's* stuff you don't want to work with. Or perhaps 100% pure resiniferatoxin, that'd be rather nasty as well, even if it didn't outright *kill* you... ;)

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44. fred on October 15, 2012 3:44 AM writes...

Hahaha I lost it at the thiophenol comment.

Someone in my lab was working with that for several months. Every day I went in trying to figure out what the god damn smell was. I described it similar to you: burning rubber with a hint of rotten chicken.

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45. Bram Cohen on December 5, 2012 4:55 PM writes...

Apparently benzenetellurol has, in fact, been synthesized. No comments about the odor - maybe it tends to form a solid quickly enough to not be a problem? https://en.wikipedia.org/wiki/Diphenyl_ditelluride

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46. Anonymous on April 15, 2013 9:21 AM writes...

So if thiols and "selenols" stink, and butyls stink, with butyl mercaptan being one of the worst thiols, what then of butyl selenomercaptan? I've seen only a few mentions of it, mostly (incorrectly based on Wikipedia) stating that it's a component of skunk stink. Never had the dubious pleasure of getting a whiff of the pure stuff, nor can I find literature on any use for it besides clearing the area.

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47. Galane on November 8, 2013 7:29 AM writes...

Something pretty high up on the stench-o-meter is decomposed Tenite. Tenite is a (typically transparent) cellulosic plastic invented in the 1930's by Eastman. They still make it, don't know if they've solved the decomposition issue.

It saw quite a bit of use in the automotive industry due to its clarity and low melting temperature. Unfortunately that temperature isn't too far above what the interior of a car in the sun with all the windows up can reach. Over time, the plastic shrinks, distorts and turns brown.

It's like the rubber doggie doo with lifelike odor that sticks to your hands, as mentioned in one of Robert Asprin's "Myth" books.

But it doesn't even take heat to get the stink going. Leave a car with Tenite parts in its interior sealed up in a dark garage for two or three decades and you'll swear someone shat and vomited in a well used litterbox and hid it in the car for all that time.

If Eastman is ever on the lookout for extra revenue, they should pull out their circa 1940 formula for Tenite. Applying some creative aging techniques to pellets of the stuff would make an excellent non-lethal (except to olfactory nerves) area denial agent.

In recent years, Eastman collaborated on a "skeleton" bodied electric guitar. Their contribution was molding the shell in Tenite. I'd hope they had the decomposition and stench issues solved!

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