Sciencemadness Discussion Board

On tri - R- Borates

The Volatile Chemist - 2-8-2014 at 14:43

It's really hard to talk about chemistry on twitter with the 120 word limit... Me 'n' Brain and force were talking about trimethyl borate and triisopropyl borate. I was considering making some of the second as I have no methanol. Just wanted to discuss some procedures for the making of organic borates.

The Volatile Chemist - 2-8-2014 at 14:52

Sorry for the double post, but just wanted to separate the topic from the ideas. So far, it has been suggested by B&F that sulfuric acid aids the formation of such borates. I have tried a mixture of isopropanol and boric acid by themselves w/o success, so I will try next with concentrated H2SO4.

Brain&Force - 2-8-2014 at 15:01

So...it appears that water is our enemy here.

The absence of water promotes the production of the ester, which is why sulfuric acid is recommended for production. If you're using 70% isopropanol, that's probably killing it (though the boric acid should produce a green flame anyway).

If you're getting yellow flames it's likely because of incomplete combustion (a problem with long chain alcohols).

Magpie - 2-8-2014 at 15:14

This may be helpful:
http://www.sciencemadness.org/talk/viewthread.php?tid=16439

The Volatile Chemist - 2-8-2014 at 15:23

Quote: Originally posted by Magpie  
This may be helpful:
http://www.sciencemadness.org/talk/viewthread.php?tid=16439

Thanks! It is helpful.

subsecret - 3-8-2014 at 08:40

In order to remove the water, you could fill a Soxhlet extractor with calcium chloride and use it as a reflux setup. It would require more solvent, but it would help to improve yield.

The Volatile Chemist - 3-8-2014 at 09:31

Quote: Originally posted by Brain&Force  
So...it appears that water is our enemy here.

The absence of water promotes the production of the ester, which is why sulfuric acid is recommended for production. If you're using 70% isopropanol, that's probably killing it (though the boric acid should produce a green flame anyway).

If you're getting yellow flames it's likely because of incomplete combustion (a problem with long chain alcohols).

I'm actually using 95% isopropanol, but it's ~6 years old, so that may be part of the problem...

Brain&Force - 3-8-2014 at 09:48

Simple salting or drying with calcium or magnesium should do the trick. If you want to use methanol, buy HEET from a hardware store - it's relatively pure methanol.

Mailinmypocket - 3-8-2014 at 11:19

Quote: Originally posted by Brain&Force  
Simple salting or drying with calcium or magnesium should do the trick. If you want to use methanol, buy HEET from a hardware store - it's relatively pure methanol.


Check the paint section of the hardware store, you can usually find methanol in larger cheaper quantities. This bottle costs something like 4.99 and they also have 4 litre size too. :)


image.jpg - 68kB

The Volatile Chemist - 4-8-2014 at 03:14

Great, thanks! I'll be able to try this in a week at best, I'm leaving for a camp today.

subsecret - 5-8-2014 at 17:07

If you buy HEET, you'll want to distill it first. The commercial product has been said to contain an oily, high-boiling impurity.

The Volatile Chemist - 10-8-2014 at 05:38

Distilling that kinda stuff would be a bit of a fire hazard, though, right?
I won't be able to try anything today, but I'll plan for tommorow.

[Edited on 8-10-2014 by The Volatile Chemist]