Low temperature storage of free radicals

• Publisher: Elsevier Science
• Year: 1956
• Tongue: English
• Weight: 261 KB
• Volume: 262
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(56)90561-0

✦ Synopsis

The National Bureau of Standards has developed a technique for capturing and storing large numbers of highly reactive molecular fragments at temperatures near absolute zero. By this method, unstable atoms and free radicals, known to exist but momentarily in flames and hot gases, are produced in an electric discharge, frozen into immobility, and trapped in solid form. Because these atoms are frozen in the excited state, they can be conveniently studied by optica1 spectroscopy.

In experiments to date the Bureau has produced solids containing atomic nitrogen and oxygen, and possibly atomic hydrogen and an unstable hydroxy (OH) molecule. These solids have very unusual properties, emitting bright glows, blue 'Yames," and colored flashes of light. When warmed 20 or 30 deg., they combine very actively, releasing large quantities of stored energy, principally as heat. Other possible fields of application include solid state physics and basic chemistry.

Here the trapped atoms could be used as powerful probes into the solids containing them. From a study of their properties, information could be obtained about the arrangement of the atoms and molecules in the solid and about the forces acting on them. Similarly the niechanism of diffusion of atoms and of reactions between atoms and molecules could be studied.

These experiments were begun at NBS in 1954 by H. P. Broida and J. R. Pellaml and are being continued by H. P. Broida, A. Bass, and 0. Lutes2 of the Bureau's temperature measurements laboratory. C. M. Herzfeld of NBS is carrying out theoretical investigations3 on the systems.