Naphthoquinone methide type near-i.r. dye: the properties and structure of 4-(2′-acetylamino-4′-diethylaminophenylimino)-1,4-dihydronaphthylidene- malononitrile
Abstract
The introduction of an acetylamino group at the 2′-position in the aniline ring of a naphthoquinone methide dye produced a red shift with a large increase in the molecular extinction coefficient in CHCI3 solution, and an intramolecular ring-closure reaction of the compound under alkaline conditions gave a new blue dye; the stereochemistry of this chromophoric system was determined by X-ray analysis.