Smelly Chemistry - Periodic Table of Videos

[@andreibusuable]

You guys make chemistry so interesting.

[@br0sRchill]

0:37 "le stink"

[@AntiProtonBoy]

I'd love to get my hands on a Tellurium based stink bomb.

[@Obsidus]

Prof. Poliakoff is amazing.

[@karmakazi219]

On a "normal day" there are 8000 gas leak reports?!?!

[@MichelDellaCompta]

I live in the city where the mercaptan leak happened, it was pretty bad..

[@TheChemiKid]

Anyone hear breaking glass @ 3:53?

[@pmarceau]

I find it interesting that a dog's sense of smell is so much more sensitive than ours, yet bad odors seem to bother them much less, if at all.

[@fackingpos]

Fart in your general direction!!!!

[@PKFreezeBETA]

It doesn't really do anything chemical, it just fools your nose into not smelling the skunk spray as much. basically, what happens is your nose gets used to smelling the skunk smell, and after a while it stops smelling quite as strong, and the tomato juices more pleasant odour is enough to mask the skunk smell. to anyone who hasn't been around the smell for very long, it still smells awful. the process is called olfactory fatigue.

[@DevilMaster]

Reason #1 is that the smell of grapefruit is not ONLY due to thiols. Reason #2 is that a substance can be perceived as having a different smell dipending on its concentration: for example indole, which smells like flowers at low concentrations, while it smells like shit (literally) at high concentrations.

[@Mivalys]

"...to see how her hair compares to mine." I loved that argument. :)

[@PINGPONGROCKSBRAH]

"Professor Moody" lol did anyone else think of Harry Potter?

[@SnowRaptor]

A few years ago, a truck carrying mercaptans tumbler over in São Paulo, triggering lots of phone calls to the firemen and to the gas company even from the other side of the city. One biker asked me in the car what happened and it took me some time to explain to him.

[@SrikarManepalli]

Nice tie Professor

[@pecfree]

WE LOVE YOU PROFESSOR! KEEP THE VIDEOS COMING GUYS!

[@RokitScientist1987]

Awesome content. I'm astonished by the amount of detail and the amount of interesting and useful information shared.

[@dflxxhunterxx2]

Hey periodic Videos! I happen to work in an oil refinery in Germany, where we actually remove naturally occurring Mercaptans from Propane and Butane using NaOH to bind them and then oxidize them with air (and some catalytic wizardry ;-) )

[@mixolydian2010]

Brilliant love all these videos..it is my current favourite channel. Thank you all very much for your work on these productions and especially to the prof for his humble and clear explanations of the chemistry involved.

[@jbrowsingj]

Fantastic work again, Brady! I'm subscribed to all of your channels, and really excited to see where you'll take them. I really appreciate how non-technical you keep them, but could you post links or a full title of any papers that are discussed in the videos? Thanks!

[@adfkjgvdjfvbdbvdkjvb]

the line "I fart in your general direction" springs to mind... ;)

[@Nikolaii2571]

Mercaptans are also used to synthesize a sedative-hypnotic called "SULFONAL" and "TRIONAL" which were widely in use a century ago.. Sulfonal was a condensation reaction of Ethyl mercaptan and Acetone.

[@killzonia]

They're talking about optical isomerism, or chirality, which involves molecules that are non-superimposable mirror images of one another (put one of your hands on top of the other; they are the same shape but are non-superimposable). They are identical in most ways apart from a few, such as how they rotate plane polarised light or, more relevantly, how they interact with biological receptors, i.e. how they smell, taste, etc.

[@sazarod]

Major points for plugging the vibration theory of olfaction!

[@heyandy889]

brady haran is like the johnny appleseed of KZbin spreading knowledge far and wide

[@urost032]

Good question. The most amazing fact about some thiols is that you can actually smell some of them in very highly diluted forms, and when in low concentrations they tend to smell quite nice(just to give you the perspective of how diluted they have to be in order to smell good(this is not in general): 1 mg of thiol per 10000000 dm3 of H2O! Amazing, ha!) Also, grapefruit contains some other compunds which give smell to it(mostly esters).

[@_starter]

And then it would be a bit late.

[@KoenigNord]

I used thiols for a long time, since they bind on elemental gold very well. with this, you can create amazingly useful functional surfaces. Luckily my thiols were to big to smell :)

[@ltericdavis2237]

If your confused, numberphile (a show made by the same guy who produces these videos, in case you don't know), made a video explaining that. KZbin's counting system stops at around 300, so it can add advertisements, if I remember that correctly.

[@ThinkingSpeck]

As I understand it, we evolved that revulsion because spoiled food tends to contain thiols. It's not that the thiols themselves are toxic in those quantities - it's just that they're very easy to detect and they tended to be associated with other chemicals which were dangerous to us.

[@BeastOfTraal]

You should do a video on chirality (left handed vs right handed molecules)

[@KennyTheB]

I can't speak explicitly for that particular compound, but generally, compounds that utilize heavier elements in this manner tend to become pretty toxic pretty quickly.

[@Jnashalt]

An introduction to an eduational kit employing the sense of smell for teaching chemistry developed by Simon Rees, Rebecca Edwards, and Jacob Cox through the Royal Society of Chemistry, Educational Techniques Group and Durham University.

[@qwaqwa1960]

I've attended a *couple* of lectures that talked about the apparent quantum effects in smell (and other biological processes)!

[@claaaaams]

excellent episode. thanks

[@dodgevipr44]

I've heard that the texture on the surface of the mentos permits the carbonation of the drink somewhere to attach, and it makes the soda fizz up.

[@tybo09]

Sorry for another question: Is the mercaptan's mercury capturing ability related to the sulfur atom? I ask because we have mercury spill kits in our equipment shop and they all contain powdered sulfur.

[@khajiit92]

elements heavier than iron come from that explosion you just mentioned. our sun is a second generation star, the heavier elements in our solar system come from an older star that exploded.

[@jmrdelorean]

being a chemist the worst thiol I had to deal with was the diester of thiol succinic acid. You had the wonderful sweet smell of the ester with the rottenness of the thiol. It was awful. If even a trace was spilled you'd smell it for weeks.

[@awesomemattg]

Is this a similar reason as why necrotic or burning flesh has a terrible stench, like when you have electro-surgery or smell dead animals?

[@mauroprovatos]

I was expecting Brady to have a sniff test.

[@heyandy889]

the professor did say something about that. apparently natural gas/methane has no smell, so something, like one of these thiols, is added in order to let people detect the gas.

[@HolyBookProductions]

One of the best Chanels on KZbin

[@knockdoun]

My Paramedical Biology Teacher once brought Durian fruit to show the class, the moment she took it out of the plastic the pungent smell filled the room and lots of people in the school thought there was a gas leak.

[@vgoj]

superb as usual. Got ot love Prof. Poliakoff.

[@adavewiley]

My high school biology teacher wanted to teach us why asparagus pee smelled the way it did. He opened a bottle of methyl mercaptan in the fume hood without noting the boiling point. It boiled away immediately, went up the fume hood, across the roof, and back down in the windows. We had to stand outside for a few hours, but I never forgot asparagus's secret ingredient.

[@Nexus2Eden]

How funny you should do this video now. I was just talking with a friend about how Skunk smell (from a dead Skunk - road kill). I was commenting on how the odor, like Camphor, sticks like glue and lasts so long. I postulated it was because they are aromatic rings, and quite stable. So the phenol compound would persist and must be highly reactive. ...and here is video on it, brilliant! :D

[@nowiecoche]

I wouldn't name "2,2-dimethyl-ethanethiol" b/c the parent chain should be named with the longest number of carbons, which is propane. But the difference between "2-methyl-2-propanethiol" and "2-methyl-2-thiol-propane", I don't know. The thiol and propane belong to two different functional groups so it has to do with that.

[@akkudakkupl]

Probably the same way we make heavy atoms - colisions. Also its not just - out of H start fusing He, out of He start to fuse Li. Because then we would end up with mostly even atomic numbered elements.

[@ammelr]

A few months ago, the Japanese isolated a compound that smells like vanilla from cow manure. Indol is commonly used in perfume, but also contributes to making poop stink. A little thiol makes garlic and grapefruit smell good, a lot smells like rotten eggs. Chemistry is very strange.

[@TheWanderingChemist]

You forgot about furfurylthiol! The coffee smell! :D

[@WolfDOuka]

I think you should do a video on the chemicals in the brain and what their function is. One interesting video could be also what if the chemicals in the human body are not balanced. :)

[@AndrewWilsonStooshie]

That's quite dangerous because if someone who genuinely smelled a gas leak had heard of the problem and didn't phone the gas company they could be in real danger.

[@007bistromath]

I had a thought while watching this video about why these chemicals might all smell so bad. It occurred to me that the characteristic carbon-sulfur-hydrogen group was like a hook, and the various mercaptans would be different things hanging off that hook. Perhaps our sense of smell works analogous to a scale, "weighing" whatever's on that hook. This would explain why the selenium and tellurium analogs are worse, as well.

[@ThinkingSpeck]

Martyn, you say you find it very unlikely that thiols' bad smell to humans is due to the vibration - you suggest instead an evolutionary explanation. I agree with your evolutionary explanation as the ultimate cause, but there must also be a proximate cause or mechanism (which I think is probably vibrational frequency). For instance, (most) birds can fly: ultimately because flight was evolutionarily advantageous in the distant past, but proximately because they now have wings and so on.

[@CaptTerrific]

Any chance we could see a followup to the sodium/water video, where you make better use of that amazing phantom camera? Thunderfoot made some very interesting observations about your theories, and the potential for the Periodic Videos to actually contribute to a new scientific discovery, instead of simply giving demos, would be amazing!

[@Jotto999]

I've read the series throughout, grew up on it. I was thinking how it'd be during the series, I probably because I've been reading HP:MOR lately.

[@callumwatson7582]

I love these videos

[@Versudan]

I'd like to see that paper about Deuterium vs Hydrogen smells Professor. I mean, Deuterium is a different atom from Hydrogen, even if it uses Hydrogen as a base. Could you possibly provide us a link to an online copy of the paper or something? I might need to read it a bit before I can accept what it says, because on the surface the paper doesn't sound like the experiment was properly thought out.

[@TheWildHaggis]

This video reeks of great stories!

[@Syltibob]

Does this mean that you can get rid of the smell from skunks with bleach?

[@en4rab]

There is a talk from TED.com on youtube here: watch?v=yzOcvINn8Iw in which Luca Turin talks about why he believes we smell vibrational frequency's and a possible mechanism for it and how he founded a company making scents for the perfume industry based on this. I found it quite compelling.

[@KialraOfDeath]

Strawman argument, beautiful.

[@UnicornStarShip]

When you talk about "left hand" and "right hand" compounds- are you talking about cis and trans isomers? One of the few things I still remember from a university chemistry class 10+ years ago....

[@Premoose2]

Hey Brady, just wondering if you guys are going to respond to Thunderf00t's newest video? Anyways, great videos like always.

[@bojor7]

i always love to see a gorgeous Schlenk Line!!!, keep bringing Organometallic Chemistry

[@Gibbsbc1]

That is some quite good evolutionary psychology.

[@Syzygy2048]

Do thiols pose health hazards? The story about the firemen and the building that had to be evacuated kind of made it sound like that.

[@JonesAndGriesmann]

I have a question for you. When the Snow melts where does the White go?

[@stepb24]

We use 2-mercaptoethanol in the lab and that stuff is stinky! Another stinky smell is anaerobic bacteria. It is amazing how such a tiny thing could stink so badly!

[@krazyking424]

Is it possible that there is a mechanism in the nose to isolate the sulphur-hydrogen bond from the triols? Then we would just be recognizing that bonded pair. I guess the issue would be if that bod was stable and how much energy would go into isolating it (also if that is actually how it's done)...

[@ExtrasAreOrdinary]

Usually "R" denotes a hydrogen or a hydrocarbon side chain (of some length).

[@Syzygy2048]

He said the building HAD to be evacuated, that sounds more like "shit just hit the fan, run for your life" - carries a completely different meaning than "the smell was so bad that people evacuated the building" which is more like "I can't stand this smell, fuck this shit I'm out of here"

[@awimachinegun]

he has some good criticisms and additions.

[@ThinkingSpeck]

Are thiols actually toxic at anything like the lowest concentrations at which they repel us? I thought they were just convenient strong-smelling markers which tended to be associated with other, more dangerous, chemical products of putrefaction.

[@Quintinohthree]

That'd be butyric acid, or butanoic acid if systematic names are more your thing. It smells because there are receptors for it in our noses. We have these receptors because it occurs in rotten foods.

[@therobotFrom94]

Do the Selenium/Tellurium compounds have similar, but worse, smells to thiols? or are they different and worse

[@nagromgreen]

So are mercaptans part of the compound beta-mercaptoethanol? We used that in intro BCEM but alas I am not a chemist.

[@Re_Kitty]

Brady, why do I keep seeing liney things in the videos?

[@stumbling]

As the prof said, many foodstuffs give off hydrogen-sulphides when they rot.

[@kentrel2]

What would happen if somebody dropped that bottle of Thiol in a room? Serious question - I'm curious just how powerful it is.

[@danieljryba]

The Prof. Should make a video explaining Right-handed vs. Left-handed molecules.

[@justrockthisworld]

i smelt it :( a lot of the alarms in the city went crazy :)) i'm happy that now i know exactly what it was. thank you! :)

[@123456789robbie]

there's a guy who makes videos called thunderf00t, and he's been recently making references to periodic videos

[@hunnis12]

Prof. Moody and Prof. Moriaty? You're the best..

[@TheGhostbuster1989]

sometimes, where the chemical is faceing is very important, especially when dealing with drugs. look for some thing called enantiomers (if i try to explain it, it would take me days)

[@salvatoreshiggerino6810]

I once had the displeasure of working as an orderly in a mental institution where an inmate had been shitting all over his cell. I emptied a whole bottle of sodium hypochlorite solution all over the place and almost killed myself with the fumes, but it was all worth it. I'm a huge fan of hypochlorites.

[@MakuziTheInuk]

if he was my science teacher i would love science again

[@HomesteadScientific]

I believe the one that goes into gas can also be called Putrescence right?

[@unvergebeneid]

If the way molecules bond chemically has an effect on how they smell and their physical properties have as well, isn't it obvious that our nose uses a combination of both principles?

[@googolplexbyte]

What if there IS a gas leak while you are using the thiols in an experiment?

[@MichaelZola]

thank you for the new channel recommendation

[@Narokkurai]

How is it possible that such a small amount can be so smelly over such a large distance? Sure, it may be able to evoke a very strong reaction in humans, but wouldn't there simply be a limitation as to how many molecules would be able to escape that far?

[@xnax1993]

God, I love the professor!

[@bullar400]

At 8:38 It is written (RSH + 3NaOCl). What does the "R" mean?

[@OnceUponATimmyy]

What is a left or right handed molecule? and what is the difference?

[@CoxTH]

The methane doesn't have any smell. That's the reason why the put those thiols into the gas. You probably mean hydrogen sulfide which makes some natural gases (those from your body, too) smell.

[@MakeRobotics]

Your tie is awesome!

[@NinjaXM0]

By left handed and right handed molecules does he mean optical isomers ?

[@inventorOz84]

what about Betamercaptoethanol which we use as a reducing agents in the biochem?