I was talking about reactive compounds the other day, but I should note that some of the reactive ones can still linger around in a peculiar manner. Acid chlorides are a good example, from both carboxylic and sulfonic acids. They’re reactive, all right – just pitch one into a bunch of amine and find out. So you’d think that if you spilled some, that their admittedly nasty aromas would be a problem that solves itself, right? They won’t last long outside the bottle; they’ll react with water and such in the air and stop stinking the place up – right?
Wrong. Some of these guys can hang around for abominable lengths of time if you don’t actively clean them up. The problem is, I think, that while they do react with water, it’s only a fast reaction under stirring conditions. In the bulk phase, the liquid acid chlorides tend to be rather thick and oily. My guess is that the outer layer does react with water (at its own pace), but that diffusion is slowly bringing more unchanged acid chloride to the surface. Where it reeks.
The sulfonyl chlorides tend to be solids, which makes the problem that much worse. The crystals don’t do the stainless-steel thing and form a reacted skin around them that seals up the inside. No, for all I can tell, tosyl chloride (the prototype sulfonyl chloride, found in organic labs around the world) will stink indefinitely. I’ve no idea of what its nose-wrinkling, headache-inducing half-life is, just that it’s very long indeed.
At least its hydrolysis product, toluenesulfonic acid, doesn’t smell. It won’t improve whatever its standing on, true, but at least you won’t know it’s there from across the room. But those oily liquid carboxylic acid chlorides stink horribly as their free acids, too, so over time, if you’re so inclined, you can note the changeover from the musty, acrid smell of the chloride to the rancid, goaty stench of the parent acid. The midpoint of the process is a treat.
So, you lazy chemists, break down and clean the stuff up. It’s not going to get any better unless you put some energy into the system (in the form of hands, elbows, and paper towels). All of our problems should clean up so well.