LIGHT ATTENUATION BY PHOTOCHEMICAL MEANS: PHOTOCHROMISM
Abstract
It was found that the photochromism of 2-(2,4-dinitrobenzyl)pyridine is not limited to this compound, but is the common property of a class of aromatic nitro compounds which possesses certain structural characteristics: the presence of a nitro and a methenyl group ortho to each other. Solvents were found to have a marked effect on the rate of the fading reactions; As were substituents in the para position of the aromatic ring of o-nitrobenzylpyridines. It was found that on irradiation with ultraviolet light, 3,3'-dinitro-4,4'-di(2-pyridylmethyl)azoxybenzene undergoes simultaneously aci-nitro tautomerization and geometrical isomerization. A new class of photochromic nitro compounds was discovered. The essential structural requirement for photochromism in these 1-aryl-2-nitroalkenes is that the nitro and phenyl groups bear a cis relationship with respect to each other. It was shown that some of the simpler o-nitrobenzyl compounds, such as o-nitroluene, are not only photochromic, but give relatively stable free radicals when irradiated with ultraviolet light. These radicals were identified as phenyl nitroxides.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1966
- Accession Number
- AD0634651
Entities
People
- Aaron L. Bluhm
- E. T. Strom
- Julius Weinstein
- Margaret E. Langmuir
Organizations
- United States Army Soldier Systems Center