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Aaysha Safare

How do we heat solvents way past their boiling points for small scale reactions ?

Catherine Shaw Follow

https://chemglass.com/pressure-vessels-heavy-wallMore

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Colin John Cook Follow

[deleted]More

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George House Follow

It's awfully difficult to reflux such small scale reactions ... Was looking for solutions to allow for screening of conditions. Thanks for your help !More

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Chief Thunder Follow

In a pressure bomb.More

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Ayesha Khan Follow

What people do is they use the green caps with PTFE liners (sometimes you also have to tape them with electrical tape). These caps allow you to heat solvents past boiling without leaking. The black caps will dissolve the glue in the liner and leak solvent at highly temps. There are red pressure relief caps that work pretty well but they will vent solvent if the pressure gets too high.More

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Andrew Ng Follow

Buy a blast shield. I do this and just tighten down the screw cap, sealing the system. Then I hear it behind a blast shield.More

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Barry Williams Follow

They make small vials with pressure relief valves which operate over 100 - 150 psigMore

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Elizabeth Peters Follow

Thanks for your help !More

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Clark Bull-Misner Follow

The vials were screw capped and (presumably) pressure safe before heating, because as you have indicated, there is a risk of catastrophic rupture.More

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Harold Clements Follow

I think maybe you can scale back your reference to “catastrophic rupture.”More

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Joseph Spear Follow

I guess I will have to convince my PI to get some. Thanks for your help !More

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Jack A. Underhill Follow

We’re not exactly blowing up a nuclear bomb here.More

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Florens de Wit Follow

Yes, 1 mL hexane in a 3 mL vial.More

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Danilo Angelo Follow

You could use other specific system (the one for hydrogenatio) if you need really high pressure such as 200 barMore

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Jamie Vander Velden Follow

Would you kindly provide some of the example of the glass tubes that you use ? I am not sure if the ones at my university are designed to withstand high pressure. Thanks for your help !More

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Amahle Gina Follow

If you do it in deuterated solvent, you might even be able to NMR it directly - as long as the tube fits easily in an NMR tube, you can add solvent around it. Wouldn’t recommend with some metal-catalyzed chem, but straight organic is doable. Just be aware that anisotropy can be observed if the tube-in-a-tube can’t spin well. Also, if the ends are sharp, you could puncture the NMR tube and end up with an ampule in the probe. Not a great look for you with the NMR technician. Still, I’ve heard of it being done with chloroform to do direct NMR of reactions or materials dissolved in carbon tet.More

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