Sciencemadness Discussion Board

Where to get sulfur monochloride?

ManyInterests - 23-1-2023 at 20:31

I wasn't sure to make a thread or ask this in organic chemistry for acetic anhydride synthesis thread.

So one of the first things I wanted to get when starting out is acetic anhydride (why I don't completely remember! But it got stuck in my mind so there!) and while I did find a source that sold some, I am no longer able to buy from them.

I've looked over some methods of making acetic anhydride, but then I saw a video that seemd to have a much simpler approach to the whole thing. Using sulfur monochloride along with anhydrous sodium acetate. the sodium acetate is easy enough, but the sulfur monochloride sounds quite interesting to make, and while I will end up with all the lab equipment and setup to make some (chlorine generator to molten sulfur and then purifying the sulfur chlorides from the dichloride and monochloride) I was wondering if there was a place where I could obtain the sulfur monochloride and avoid the hassle.

Any ideas? I'm in Canada and I know where to get elemental sulfur, but that's it.

j_sum1 - 23-1-2023 at 21:15

I would expect that it is easier to make than buy.

Sulfur chlorides are not incredibly stable: they fume in air and decompose in water. Ok, that is hardly unique, but it tends to make for something that is supplied to a nice market only and is expensive to ship. It may also be problematic convincing whoever that you have a legitimate need for it.

OTOH, sulfur chlorides are not especially difficult to make. Storage is a different issue, but you probably do not want to do that anyway.

ManyInterests - 23-1-2023 at 21:28

Quote: Originally posted by j_sum1  
I would expect that it is easier to make than buy.

Sulfur chlorides are not incredibly stable: they fume in air and decompose in water. Ok, that is hardly unique, but it tends to make for something that is supplied to a nice market only and is expensive to ship. It may also be problematic convincing whoever that you have a legitimate need for it.

OTOH, sulfur chlorides are not especially difficult to make. Storage is a different issue, but you probably do not want to do that anyway.


Sounds good. Yeah I saw a video from Doug's Lab where he makes bisulfur dichloride and then purifies to draw out only the monochloride (there is a substantial temperature difference between when one will distill out vs. the other, making the process easier than other distillations).

I am going to agree that this is going to be more fun and interesting to make than it is to buy. And I will likely use it as soon as I make it anyway.

woelen - 24-1-2023 at 00:54

It's not really difficult, but I strongly recommend to you to assess the risks before doing the synthesis. I personally would do this outside if you have the option. The final product, but also the intermediate mix of sulfur chlorides, has a nasty smell, which tends to linger and tends to stick to furniture, curtains, etc. After the initial smell is gone, you get a certain "sulfurous" smell, which is noticeable for a long time (days at least). It is not really nauseating, but in the long run, it becomes annoying to notice that smell, each time you go into your work place.

Of course, there is also an immediate risk, e.g. if your chlorine generator leaks and lots of Cl2 escape into the air. A whiff of chlorine won't kill you, but a large amount of Cl2 certainly is a risk to take into account! If you work outside on a day with a gentle breeze, or in a good fumehood, then that risk is much lower.

ManyInterests - 24-1-2023 at 19:33

Quote: Originally posted by woelen  
It's not really difficult, but I strongly recommend to you to assess the risks before doing the synthesis. I personally would do this outside if you have the option. The final product, but also the intermediate mix of sulfur chlorides, has a nasty smell, which tends to linger and tends to stick to furniture, curtains, etc. After the initial smell is gone, you get a certain "sulfurous" smell, which is noticeable for a long time (days at least). It is not really nauseating, but in the long run, it becomes annoying to notice that smell, each time you go into your work place.

Of course, there is also an immediate risk, e.g. if your chlorine generator leaks and lots of Cl2 escape into the air. A whiff of chlorine won't kill you, but a large amount of Cl2 certainly is a risk to take into account! If you work outside on a day with a gentle breeze, or in a good fumehood, then that risk is much lower.


I've had enough gas inhalation issues in the past that I've finally been able to find a seller who will sell proper gas masks with appropriate filters for my needs. I now have a gas mask with a filter that is rated for acid gasses, sulfur dioxide, chlorine and chlorine containing organic pesticides, phosgene, and nitrogen compounds.

I tried it when making a PETN nitration and it protected me completely against the fumes. It'll do nicely for both the chlorine and the sulfur smells.

My only concern is far more about the neighbors who might smell it and think 'what is that smell?' I really don't want to be drawing attention to myself at all. My balcony is nice, but this type of synthesis will take hours at the very least and I will probably have to do it past midnight when everyone else is asleep and no one else is on their balcony.

woelen - 25-1-2023 at 13:31

That sounds quite shady. If you are doing "strange" things on your balcony in the small hours of the night, then that certainly will make people suspicious, if they see it. I would try to construct a good scrubber, which absorbs Cl2 and any vapors of sulfur chlorides (a solution of NaOH will work very well, combined with a good bubbler). If you do that, then you probably will be able to do things at normal evening hours without weird smells and raise less suspicion.

Another thing may be that you have to accept that not all things are acceptable in every house. I myself have a big garden, with lots of room around the house, so I do not have to worry about such things, but in the past I lived in a flat with a balcony, and during those years I accepted that many bigger experiments and setups were not possible in a reasonably responsible way. Know your limitations!

ManyInterests - 25-1-2023 at 17:35

I will definitely take that into consideration. I will need to do a lot more research into it and possibly find a different venue to do this specific synthesis in. So far I haven't done any research on scrubbers but now that you mention it, that sounds like a very good idea. I like being responsible! :D