How to avoid explosions when heating small sealed tubes - Journal of

Using reusable, screw-capped, thick-walled test tubes as high-pressure containment vessels. Keywords (Audience):. Second-Year Undergraduate. Keywords ...
2 downloads 0 Views 245KB Size
How to Avold Explosions when Heating Small Sealed Tubes Reactions in small closed glass containers at high temperatures are often tedious due to the difficulties in sealing and re-opening thick-walled Pyrex tubing. We suggest here a very simple device which allows even standard sealed NMR tubes to be used at temperatures as high as 180' C with liquid samples or solvents as volatile as methanol. The method employs a reusable, screwcapped, thick-walled test tuhe as a high-pressure containment vessel. The sealed tuhe containing the solution to be heated is introduced into a SVL test tuhe (1.8 mm wall thickness, from Carnick: tuhe, 703-01;cup 708-67) which is partly filled with the solvent used for the reaction. Thus pressure within the sealed tube is equalized on the outside during heating; and this prevents the sealed tuhe from exploding.

-SVL

sealed tube solvent

J. Cossy A. Flegenbaum Laboratoire de Photochlmie. U.A. 459 U. E. R. Sclen~es,51062 Reims Cedex, France

1014

Journal of Chemical gducation

+ ~oduct

tube

SoIYent oil both