[MOTOBALL]

Many years ago I prepared 1,5-hexadiene-3,4-diol (mixture of the erythro and threo isomers) as a syrup by the action of a Zn/Cu couple on acrolein.

The product was purified by distillation under reduced pressure to give a syrup; b.p. 92 Deg/10 mm Hg; refractive index Na D line @ 21 deg =  1.4745
Lit. b.p 55 deg/0.02 mm Hg; Na D line @ 25 deg = 1.4739.

A solution of this syrup in pyridine was treated with CH3SO2Cl (3% xs); extraction with CHCl3 and the usual workup gave a yellow syrup; TLC showed 1 minor (fast-moving) component, and 1 major (slower-moving) component. The IR spectrum showed no -OH absorption.

On attempted distillation under reduced pressure (7 mm Hg) the product decomposed explosively at ca. 120 deg (oil bath temp.).
My recollection is that a nasty black residue and some shattered glassware was the result.

I had previously recrystallized mesylates of carbohydrates without mishap.

I have subsequently encountered, via the internet, the occasional comment regarding the explosivity of mesylates.

Any comments and literature references would be appreciated.

Regards,
MOTOBALL

[rolnor]

Its strange, there is no red-ox possible really, maybe elimination?

[clarkstill]

Elimination-electrocyclization-elimination to give benzene?

Honestly no idea, but a fun thought experiment.

[rolnor]

Interesting idea, I think of a similar case, if you mix acetone with conc. sulphuric acid you get mesitylene.

[Babcock_Hall]

I wonder whether it would be helpful to calculate the oxygen balance of this molecule.  Explosives are sometimes formulated so that their combined oxygen balance is close to zero, although this is far from being always true.  Suzanne Bell's book Forensic Chemistry talks about this a little on pp. 371-372.  It is also discussed in Chapter 5 of a forensic chemistry book (Jay Siegel, ed.; Wiley Blackwell) by John Goodpaster, starting at p. 189.  The oxygen balance = (mass of oxygen released or consumed)/(mass of explosive).

[rolnor]

I think sulphur is not possible to oxidize, nor carbon really, not in any explosive way. What would be the products from the explosion?

[Babcock_Hall]

One starts by writing a balanced equation assuming that the products are carbon dioxide, water, and nitrogen gas (if nitrogen is present).  The chapter I am consulting on this does not indicate what the product to use for sulfur.  I would hazard a guess that it is SO₃. 

[MOTOBALL]

I used different words in yet another Google search of this topic, and finally turned up something relevant.

This is from a PhD thesis at Caltech on functionalized polymers that contained furan rings with -CH2OH groups.
A polymer with furan rings, each bearing 2 vicinal -CH2OH groups was converted into the di-O-mesylate.
A portion of the polymer was heated in a thermogravimetric analyzer and I'll cut/paste from the thesis here:-

"The solid polymer has been subjected to thermal gravimetric
analysis.... The loss of methanesulfonic acid is proposed as the cause of mass loss.
This polymer loses mass in an extraodinarily clean fashion, and at a very low temperature.
Onset of mass loss is at 220 °C, a temperature easily reached in solution. The
onset of mass loss is visually observable: a cloud of smoke rises from the
sample at the same time the spike is recorded. The apparent rise in mass is
associated with the dramatic way the gases leave the polymer sample--the
TGA balance pan is pushed down by the force of exiting masses, giving the
appearance of mass gain." E. Burns, PhD Thesis, Caltech, 1993

Both O-mesyl groups are eliminated to leave the furan ring bearing now two vicinal, methylene (=CH2) groups.

My molecule, C8H14O6S2 = 270 M Wt and I distilled 6.0 g, which is 0.0222 moles.
This should release 2 x 0.0222 = 0.0444 moles of CH3SO2OH, which occupies 0.995 L at NTP. (293 C/ 760 mm Hg)
This corresponds to 0.995 x 393/293 x 760/7 = 145 L at 120 C & 7 mm Hg.

No wonder that the distillation apparatus was destroyed!!!

Regards,

MOTOBALL

[rolnor]

One starts by writing a balanced equation assuming that the products are carbon dioxide, water, and nitrogen gas (if nitrogen is present).  The chapter I am consulting on this does not indicate what the product to use for sulfur.  I would hazard a guess that it is SO₃.

To get SO3 you need to reduce carbon? There is no net release of energy?

[Babcock_Hall]

rolnor, I wrote to the author of the chapter to clarify this point.  I might start a thread on oxygen balance when I have time.

[rolnor]

OK. If you have nitrogroups you get a lot of energy if you move oxygen to carbon from nitrogen and release nitrogen+carbondioxide, this is will not happen when moving oxygen from sulphur to carbon or the other way around.

[Orcio_87]

I think sulphur is not possible to oxidize, nor carbon really, not in any explosive way. What would be the products from the explosion?

In therm of the energy I think you are right. But maybe it is not about the energy or rather the amount of the forming gases.

If you have nitrogroups you get a lot of energy if you move oxygen to carbon from nitrogen and release nitrogen+carbondioxide, this is will not happen when moving oxygen from sulphur to carbon or the other way around.

Lot of energy from moving -NO₂ oxygen to carbon - true. But - moving oxygen from -SO₃H to the carbon.... - also true, because these are completely different bonds.

But - the sulfur is dont important here. Rather - how many moles of O₂ are consumed and how many moles of gases will be the products (for example - hydrazine vs ethylene).

[rolnor]

No, there is no large energy change reacting SO3 with carbon to form CO2 and sulphur. You can use nitric acid as oxidant in rocket-fuel, but not sulphuric acid. You can not substitute potassium nitrate in gun powder with sodium sulphate

[MOTOBALL]

I would like to return this thread (after it being hijacked into a phys. chem. discussion) back to the original post.

Does anyone have any awareness of vigourous/explosive decomposition of O-methanesulphonyl compounds?

Regards,

MOTOBALL

[Babcock_Hall]

I regret bringing up oxygen balance, which turned out to be an unfruitful tangent.  No, I have not heard of this phenomenon previously.  Given that mesylates are a common derivative, I wonder why.