Fulgide

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General chemical structure of fulgides in the uncyclized form. In order to cyclize, at least one of the four R groups must be an aryl group.

In

ultraviolet light, converting between the E and Z isomers, both of which are typically colorless compounds. Unlike the more-stable Z isomer, the E isomer can also undergo a photochemically-induced electrocyclic reaction, forming a new ring and becoming a distinctly colored product called the C form.[1]
It is thus the two-step ZC isomerization that is the photochromic change starting from the stable uncyclized form.

History

The first compound of this class was synthesized in 1905, with the name based on the Latin word "fulgere", meaning shiny, for the shiny and large variety of colors of the

photostability were synthesized.[3][4]

Derivatives

Various other

carbonyl
structures have been studied, in addition to the original succinic anhydride. The goals includ controlling various chemical properties, photochemical properties, and embedding of this structural motif in more complex molecules.

Fulgimide

General chemical structure of fulgiimdes

Fulgimide is an analog that has

carboxylic acid anhydride towards hydrolysis. It also involves a less-complicated synthetic process for attaching substituents onto the structural core.[1] The nitrogen atom provides a point of attachment for chains that can be cross-linked to form polymers.[5]

Fulgenolide

Fulgenolide is a

alkyl link. Fulgenolides have a larger quantum yield than other fulgide derivative and has a λmax of the C form in near IR-region.[1]

Fulgenate

Fulgenate is a diester analog. However, fulgenates do not have photochromic characteristics.[1]

References