Purging alcohol with NO gas

Topic created by Anon
on Sat, 14 Jan 2023 at 21:16

Anon said on Sat, 14 Jan 2023 at 21:16...

What is to stop someone from just purging an alcohol with NO gas to make a popper? It seems like a cleaner way to do this rather than adding shit into the alcohol, neutralizing the acid, seperating the water, drying it, ect.

The Professor said on Sun, 15 Jan 2023 at 00:22...

The liquid batch phase is the safest, simplest, highest yield process for the layman.

It IS a two step process (let the ingredients fall apart into ions in a solvent (water in this case), then they will recombine into product and salt water, but it is comparatively safe.

The activation energy (amount of energy required to start a reaction) is extremely low. and it all takes place at nearly STP (standard temperature and pressure at sea level).

By contrast, VAPOR phase preparation (I make NUBLU in vapor phase, but only because I enjoy chemistry) requires high heat (about 150C) and pressure to have meaningful results. That makes it a very likely explosion hazard to the un-prepared.

It SOUNDS simple, to let gas bubble through liquid; but in fact the alcohol is NOT binding with NO, the Methyl groups that come FROM the alcohol are binding to NO.

Nothing is stopping anyone except the vanishing yield and explosion hazard

Curious Popper's User said on Sun, 15 Jan 2023 at 03:23...

"but in fact the alcohol is NOT binding with NO, the Methyl groups that come FROM the alcohol are binding to NO"... Professor, would you mind explaining the difference? I am curious to understand what this sentence means...

The Professor said on Sun, 15 Jan 2023 at 18:25...

I'll try, I'm not sure what part doesn't make sense to you, so I may say some things that are obvious to you. I don't want to offend anybody, so if I say something that sounds condescending, just ignore it as me trying to keep myself on point (I am easy to confuse and often tangential)

At room temperatures and pressure (and thereabout), the liquid phase process is a two- step.

Reactants are introduced to a solvent, where they fall apart into ions.

NaNo2 becomes Na+ and NO2-
HCL becomes H+ and Cl- ions

The solvent is water, H2O

In this ion swap, Na+ and Cl- bins to form the waste product NaCl (common table salt).

Also, H+ and NO2- form HNO2 (nitritrous acid)

Next, the HNO2 and alcohol meet, and the weak nitrous acid starts to nitrosate the alcohol.

If the alcohol is butanol, for example, HNO2 and C4H10O form butyl nitrite, C4H9NO2 all numbers being subs, not exponents or integers)

A simple formula for butanol that shows it's structure a bit better is
CH3CH2CH2CH2OH. It's still C4H10O, just laid out so you can visualize the geometry.

CH2 is methylene. Butanol has three of these groups with a hydroxide radical at one end (OH)

You can visualize nitrites acid HNO2) as HNONO

The product, butyl nitrite (C4H9NO2), can be visualized as CH3CH2CH2CH2ONO

So
CH3CH2CH2CH2OH
Meets
HNONO
And forms
CH3CH2CH2CH2ONO

Just looking at the molecules, it SEEMS like if you take butanol, knock off the hydroxyl group (OH) and replace it with No2 (ONO visually) that would create butyl nitrite in one simple step

And that IS true, excepting that the reaction energy required to do that is something like 3 bar of pressure and 150C of heat, with both butanol and ONO in gaseous state.

Some people try to bubble NO2 had through liquid butanol, but the activation energy doesn't exist to create a meaningful yield.

What DOES work at or near STP is the two step, liquid phase process. The original source of the NO2 is now nitritrous acid (HNO2 (visualized as HONO); when it district's to H+ and ONO- , which happens readily at about 47kcal/mol of activation energy (a very low amount of energy)

Does that make any more sense?

Anon said on Sun, 15 Jan 2023 at 22:46...

I feel like I am asking a dumb question because my basis is poor.

So, are you saying that bubbling NO2 into water will produce the nitritrous acid you need?

The Professor said on Sun, 15 Jan 2023 at 23:35...

No, many people think that will work, and it will, but at 150 Celsius and 3 bar of pressure.

At or near STP (standard temperature and pressure) bubbling gas through liquid achieves nothing, since there is not enough activation energy

Curious Popper's User said on Mon, 16 Jan 2023 at 00:39...

Thank you Professor, yes that explained it... what I failed to understand first was that alcohol is R-OH, but only the R reacts, right?

The Professor said on Mon, 16 Jan 2023 at 17:23...

R represents an Alkyl group
OH is a hydroxyl group
R-OH is called an alkanol

It's a shorthand what of saying one of several possible alcohols, instead of having to repeat them individually (like pentanol, butanol propanol, etc)

Urea Master said on Tue, 17 Jan 2023 at 04:25...

Purging with NO will not work at STP nor will NO2. N2O3 is interesting to try something with. Bubbling pure N2O3 through NaOH will give you a solution of NaNO2. I had some success with this at one point, and I changed some reaction parameters and ended with something that smelled just like an attempt at making the ester with degraded NaNO2. My reaction vessels days later had an acid in solution condensed on the walls, so I think that part of the experiment was not cold/dry enough in this particular run.

Look through the patents on alkyl nitrites, and ignore the ones focusing on methyl nitrite. You will find several out there mentioning a lot of heat and pressure and enormous reactors, i.e. columns 10 meters tall. Some of us can do a cryo experiment, but a column that large is too much bother for a guy like me.

The Professor said on Tue, 17 Jan 2023 at 17:18...

Yep, N2O3 (a transient stage in the esterification process that's responsible for 'surface reactions') isn't going to work very well at STP.

That's a good analogy (it will likely end up smelling like a partially nitrosated alcohol, which it will be, but not enough to have good effects)