Sciencemadness Discussion Board - How to get started in sulfur organic chemistry?

How to get started in sulfur organic chemistry?

Cou - 27-3-2016 at 21:36

I must have an odd nose in that I like the smell of organosulfur compounds, even H2S. To me H2S is reminiscent of freshly scrambled eggs in low concentrations, not rotten eggs, and makes me hungry for scrambled eggs. I also like the smell of the ethanethiol added to propane. Elemental sulfur is also interesting, a unique yellow substance with many allotropes and a low melting + boiling point. Truffle oil (2,4-Dithiapentane dissolved in olive oil) smells quite nice.

One of my dreams is to find out what thioacetone smells like, but I'll have to do that in a very remote area, probably in the middle of the Nevada desert.

Since H2S is one of the starting points for organosulfur synthesis, I'm about to make a Kipp apparatus for generating H2S from iron sulfide, which I make from elemental sulfur. I'm very new to organic chemistry involving sulfur, such as thiols and sulfides. Apparently it's possible to make ethanethiol by bubbling H2S in ethanol with an alumina catalyst, but I'm not sure how this works in practice. Or:

Quote: Originally posted by Metacelsus

Would ethanol and aluminum sulfide react to form ethanethiol at room temperature? I've heard of ethanol and Al2S3 reacting at high temperatures to produce diethyl sulfide and ethanethiol, but I'm not sure if the same thing would happen at 25 C.
https://en.wikipedia.org/wiki/Aluminium_sulfide
http://books.google.com/books?id=BPcxrmIgLKMC

Another way would be sodium hydrosulfide and an ethyl halide:
https://en.wikipedia.org/wiki/Ethanethiol

[Edited on 28-3-2016 by Cou]

Oscilllator - 27-3-2016 at 22:47

I would suggest starting by buying a suitable gas mask. It doesn't matter how nice you think it smells, sulfurous gasses have a nasty habit of being quite deadly.
After that you could buy a whole bunch of NaOH, as you'll be needing loads of the stuff to clean your glassware of all the horrific tars you will be producing.

As far as sulfur experiments go, I would recommend perhaps starting off with making sulfur chloride. I know it's inorganic but it will give you some experience dealing with gasses, and I found the synthesis to be terrific fun.

aga - 28-3-2016 at 00:25

... and hot toluene to (eventually) get rid of stubborn elemental sulphur deposits inside the glass.

Volanschemia - 28-3-2016 at 00:32

2-Propanethione can actually be made reasonably easily. I think there was a thread on it somewhere.

I also don't think you would need to go to the Nevada if you made it in extremely small amount.

Oscilllator - 28-3-2016 at 01:55

Quote: Originally posted by aga

... and hot toluene to (eventually) get rid of stubborn elemental sulphur deposits inside the glass.

Hot sodium hydroxide works too, and is less expensive as you only need a spoonful. It also isn't flammable, unlike toluene with which I have had an unfortunate accident with in the past.

aga - 28-3-2016 at 08:46

1. Hot sodium hydroxide
2. Hot Toluene

Gimme #2 any day (and i'm a smoker)

Cou - 28-3-2016 at 12:34

Wikipedia says thioacetone smells "fearful" and I can't find any info on what it smells like, other than that it makes everyone downwind puke.

Two chemists cracked thioacetone , and when they went to a restaurant, the entire restaurant gave them angry stares while the waitress sprayed them with deodorant.

[Edited on 28-3-2016 by Cou]

aga - 28-3-2016 at 12:44

Perhaps one day Cou will actually do some chemistry, however mundane, and then actually have something to talk about on SM.

Not today, clearly.

Personally i'd be really pleased to see Cou grow a copper sulphate crystal, convert NaHCO₃ to Na₂CO₃, recrystallise NaCl, - anything other than this pointless garbage.

I know what i post is <strike>quite</strike> often utter rubbish, but at least it's Labelled as such !

Edit:

You'd get more respect (from me at least) if you had a go at blogfast's calclus questions, AND your posts attempting the questions would be more welcome there, plus you'd learn a lot.

That would take Brain effort though, and not just Google-effort, which might explain why there's just the teacher and a drunkard there.

[Edited on 28-3-2016 by aga]

j_sum1 - 28-3-2016 at 15:18

Cou
This looks like a giant step in the wrong direction. And this is coming from someone who also finds H2S relatively inoffensive. There are so many interesting fields to get into (with your new glassware) and you choose the one that is likely to irritate the maximum number of people.

Just remember that a single drop of thioacetone causes spontaneous vomiting at a quarter mile. Air quality is improved through having NO2 vapours around -- those same ones that gave you a cancer scare not too long ago.

If you must persist with this lunatic idea, I recommend you read things I won't work with. If you can mitigate against all of these containment issues then you are a better chemist than pretty much everyone here I would suggest. You are going to need a pretty sophisticated closed system and a fume hood capable of incinerating the exhaust.

I think this train of thought is (a) unrealistic and (b) has no practical or theoretical benefit.
There is no upside to this one.

[edit]
Cou, also read the blog comments in the post I linked. Some of the anecdotes from experienced chemists are insightful on this one.
I am just going to take their word for it.

[Edited on 28-3-2016 by j_sum1]

Cou - 28-3-2016 at 15:49

Quote: Originally posted by j_sum1

Just remember that a single drop of thioacetone causes spontaneous vomiting at a quarter mile. Air quality is improved through having NO2 vapours around -- those same ones that gave you a cancer scare not too long ago.

I never made NO2 before and said I made it, which proves that you're just making stuff up now. Nor did I say I was going to make thioacetone in a populated area.

EDIT: Why does everyone on the forum pick arguments with me, and then accuse me of stirring up shit? I just want to get into organosulfur chemistry.

[Edited on 28-3-2016 by Cou]

AvBaeyer - 28-3-2016 at 19:34

I agree most heartily with j-sum. What you are proposing to do is utterly ridiculous - especially from someone so concerned about legalities. If you are so interested in organosulfur chemistry, why not try to isolate some of the naturally occurring sulfur compounds from, for example, garlic? Some of these compounds (such allylic isothiocyanates) have very interesting properties and as a bonus, working with them won't put you in the slammer.

AvB

j_sum1 - 28-3-2016 at 19:36

You previously started several threads concerned about cancer. I might be mistaken but I thought NOx gases were on the list of things you wanted to avoid. If I am mistaken then I apologise. The point remains that launching into organosulfur chemistry without iutstanding gas control equipment and a lot of experience is a bad idea.

Crowfjord - 28-3-2016 at 20:10

How about alkyl thiosulfates (Bunte salts)? They are easily prepared from alkyl halides, preferably bromides or iodides, and sodium thiosulfate. They can also serve as precursors to alkyl sulfides and disulfides, I think, by relatively simple means.

Texium - 28-3-2016 at 20:18

I'm pretty sure it was SO₃ that he was concerned about getting cancer from, not NO_x
Either way, it's a good point- this thread is clearly just another load of bull and dodging the accusation due to a technicality is a classic Cou denial strategy that I'm sadly starting to get very used to seeing.

aga - 29-3-2016 at 13:02

Quote: Originally posted by zts16

clearly just another load of bull and dodging the accusation due to a technicality is a classic ... denial strategy that I'm sadly starting to get very used to seeing.

After a while you just see the pattern, irrespective of the actual word content, topic, answers/replies, supposedly unique username etc.

Although you'll have no hard facts, you'll just know.

Welcome to the Matrix neo16.

Cou - 29-3-2016 at 13:23

Since the square-shaped property which I live on is about 11940 square meters or 2.95 acres, assuming that I'm in the center of the yard, and gas diffuses equally in all directions (X, Y, and vertical Z axis), the gas will take up a hemisphere of radius (11940/2) meters by the time it dilutes to a property line, which in this case has a volume of 4.455x10^14 liters. If you make 1 liter of H2S, as an example, that dilutes to 1 / 4.455×10^14 * 1 quadrillion = about 2.24 PPQ, parts per quadrillion. Far, far below the threshold for smell, in fact even lower than the natural concentration. However this is just a rough approximation, not accounting for wind.

[Edited on 29-3-2016 by Cou]

aga - 29-3-2016 at 13:40

Despite that last being a Category 14A7 post ...

... modelling gas/particle dispersion versus where-it-will-land was the only 'proper' mathsy thing i ever (half) converted into a commercial program.

The main equation was called the 'Gaussian Plume Dispersion Theorem'.

Basically predict the location and concentration of stuff falling from a plume of factory chimney smoke, based on wind direction, volume of stuff and 'mixing height' as i dimly recall :-

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

Amazingly that was done graphically on a BBC micro !

[Edited on 29-3-2016 by aga]

Cou - 29-3-2016 at 13:47

The way I calculated is assuming that the gas is evenly distributed when it reaches the property line, which isn't how diffusion works. But in a real case of diffusion, the peak concentration is lower at a given distance from the source, and since it's gonna be lower than 2.24 PPQ, no reason to calculate it.

But none of this matters, because wind will screw things up. What if the wind is blowing toward your neighbor, will the concentration become high enough to smell once it gets there?

[Edited on 29-3-2016 by Cou]

j_sum1 - 29-3-2016 at 14:16

Your assumption of even dispersion is a best case scenario and not a reasonable approximation. You are going to get some laminar flow in the air and your gas will be pushed in one direction more than others. You need to factor in the rate of production too.

Making the gas without collecting it... what's the point? If you were making it to feed into another reaction, I might understand better.

1litre of H2S is rather small. That's 0.05 mole scale. That equates to less than half a teaspoon of sulfur as your starting material. That's ok. But I am wondering what you will do with a small amount. We are talking about a substance that is a nuisance at very small quantities but not very useful untul you get larger amounts. And of course it is dangerous at higher amounts. It makes for a tricky beast.

If you showed a clear objective or some kind of sense of direction you might get a different response from members here. Your deleted comment about truffle odour was at least interesting. That's the conversation we should be having - how to synth that compound. If part of that process is feeding H2S into your reaction then we can then have a discussion about containment, scrubbing waste gas, nuisance thtesholds and location, danger threshold, olfactory desensitisation and detection. Right now we are talking stink bombs which is all pretty juvenile.

By all means take a few grams of FeS and some acid down to the local abandoned quarry and do payback to the skunks. But don't pretend it is chemistry.

Cou - 29-3-2016 at 14:24

Quote: Originally posted by j_sum1

If you showed a clear objective or some kind of sense of direction you might get a different response from members here. Your deleted comment about truffle odour was at least interesting. That's the conversation we should be having - how to synth that compound. If part of that process is feeding H2S into your reaction then we can then have a discussion about containment, scrubbing waste gas, nuisance thtesholds and location, danger threshold, olfactory desensitisation and detection. Right now we are talking stink bombs which is all pretty juvenile.

I omitted the endgoal for the sake of this safety discussion, as to if you did make 1 liter of H2S and didn't react any of it, would neighbors smell it? 2.2 PPQ is so low that you can get away with making more than 1 liter, probably. But then it gets so complex when you factor in laminar flow and wind, that the best way to solve this is probably with plain experimentation: make some H2S, have someone with a sensitive nose stand downwind at the edge of the property, ask if they smell it.

As for the truffle odor, which is 2,4-dithiapentane (one of the better smelling sulfurous vapors, it's in truffle oil), my goal is to make that in a non-industrial home setting. the first reaction I can find is with methanethiol and formaldehyde, methanethiol being industrially produced from H2S bubbled in methane over an alumina catalyst, but once you start getting into catalysts it gets hard to do on an amateur scale.

[Edited on 29-3-2016 by Cou]

Texium - 29-3-2016 at 14:30

Quote: Originally posted by aga

Quote: Originally posted by zts16

clearly just another load of bull and dodging the accusation due to a technicality is a classic ... denial strategy that I'm sadly starting to get very used to seeing.

Psh... Make no mistake, I still think that your multiple accounts owned by one meta-troll conspiracy is utterly ridiculous. Cou is just Cou.

Cou - 29-3-2016 at 16:00

Oh dear, I made a huge mistake, forgot to square root the square meters value before getting radius:
Concentration would actually be about 1.46 PPB, which is barely perceptible still.

[Edited on 30-3-2016 by Cou]

j_sum1 - 29-3-2016 at 17:30

I think there are three issues that relate to the way that you are perceived, Cou.

The first is a lack of a clearly-stated objective. Or when you do state what you aim to achieve in your experiments, that goal shifts and changes. It makes it hard to make critically-constructive comments since we really don't know what you are aiming for. There is a world of difference between synthesising truffle scents and making stink bombs to sell -- both of which you have mentioned in relation to organosulfur chemistry.

The second is a disconnect between some of the ideas you present and what can be gleaned about your situation. On the one hand you are risk-averse and wanting to avoid all noxious chemicals for health reasons. On the other hand you want to play with some nasty sulfur compounds that most people will not touch. You are nervous about how your community and police might react to your practice of chemistry and yet you now want to advertise your presence in the most vile-smelling way possible. You make a big noise about not having glassware and therefore lack in experience and then you want to make something sophisticated like 2,4-dithiapentane. You make a hash job of mathematically modelling a chemical plume (something I would never attempt with any expectation of getting a realistic result -- but then I have done some fluid mechanics.) But you engage in no discussion of apparatus, safety procedures or containment. It is difficult to take such things seriously. Moreover, when people have commented on your ideas you have shown disregard for their advice or complained that they are attacking you personally.

Thirdly, you lack a sense of proportion -- at least in the way you express yourself. You have vacillated wildly between paranoia and naive overconfidence. You have appeared obsessed over minutiae and at the same time overlooked some basic considerations.

Why don't you open a new thread on your target compound. Provide some links of what you have been reading Give details of your intended setup. Provide us with problems that you foresee and your proposed solutions and invite some critique on your method. You will get some helpful advice for sure. Others will learn a whole lot. It will be a really valuable exercise. And when you get your result you will have a nice procedure that others will want to duplicate.

quantumcorespacealchemyst - 5-4-2016 at 19:15

Quote: Originally posted by Cou

One of my dreams is to find out what thioacetone smells like, but I'll have to do that in a very remote area, probably in the middle of the Nevada desert.
[Edited on 28-3-2016 by Cou]

then you can haloform it !!!!!!!

and hobnob with all the off planet visitors. yeah! go alien technology! whoot whoot!!!!!!!
hey, maybe they have sulfur-organic containing biology and that's why they meet out in the middle of the nevada desert, so no one will smell them

[Edited on 6-4-2016 by quantumcorespacealchemyst]

quantumcorespacealchemyst - 5-4-2016 at 19:27

Quote: Originally posted by Cou

As for the truffle odor, which is 2,4-dithiapentane (one of the better smelling sulfurous vapors, it's in truffle oil), my goal is to make that in a non-industrial home setting. the first reaction I can find is with methanethiol and formaldehyde, methanethiol being industrially produced from H2S bubbled in methane over an alumina catalyst, but once you start getting into catalysts it gets hard to do on an amateur scale.

[Edited on 29-3-2016 by Cou]

you may be able to make some columns, at least to begin with, horizontal tubes, from glass blowing suppliers. check out glasscraft.com, there is a borosilicate tube section with diameter and thickness listed, there is simax, chinese, and schott tubing and rod COE 33 (coefficient of expansion).
http://www.glasscraftinc.com/home/gla/smartlist_2000/borosil...

you could just make long columns or get an oxy propane setup with a makeshift lathe and form it.

mostly unrelated
( a sulfuric acid generator could probably be built this way too, akin to the "dangerous acids made safely by home chemist" article in Popular Science Jul 1934. it is here on the forum. they used iron (?) oxide, not even V2O5, so with vanadium pentoxide it should work better.) i misplaced the link, here it is on google books for now, although it's mostly unrelated, https://books.google.com/books?id=YSgDAAAAMBAJ&pg=PA60&a...

[Edited on 6-4-2016 by quantumcorespacealchemyst]