Synthesis and photochromic properties of some fluorine-containing naphthopyrans

Publisher Summary
This chapter discusses that significant advances in our understanding of the photochromic properties of naphthopyrans that have been made in the past decade Such is the structural diversity of naphthopyrans now available that it is possible to achieve almost any shade of any color. Furthermore, control of the fade rate with half-lives of less than a second to many hours is possible, thereby supplementing the fast and strong coloration and increasing the potential applications of these long-lived materials. Their facile synthesis from readily available precursors has allowed the commercial development of naphthopyrans to proceed at a good pace through the efforts of a small number of research groups linked to international manufacturers. The major end user is the ophthalmic industry. Brown or grey sun lenses can now be based on a single photochromic naphthopyran, whereas less than 20 years ago, multicomponent lenses were the norm. Naphthopyrans are used in security inks and as identity markers in a variety of products. Future uses in cosmetic applications and as devices are under development.

Chapter 3 – Photochromic naphthopyrans

Synthesis and Photochrmic Characteristics of 1,3-Dihydrospiro[2H-indole-2,3′-[3H-]pyrimido[5,4-f][1,4]benzoxazines] and 1,3-Dihydrospiro[2H-indole-2,7′[7H]thiazolo[5,4-f][1,4]benzoxazines]



Two new series of 1,3-dihydrospiro[2H-indole-ozazine] derivatives were synthesized, the 1,3-dihydrospiro[2H-indole-2,3′-[3H]pyrimido[5,4]pyrimido[5,4-f][1,4]benzoxaines] 4-10 and the 1,3-dihydrospiro[2H-indole2,7′-[7H]thiazolo-[5,4-f][1,4]benzoxaines] 11–17 These series extend the available range of photochromic properties (rate constant of thermal bleaching, UV/VIS spectrum of the opened coloured form, and photocoloration yield), an interesting feature of variable-transmission materials The synthesis of these compounds (Scheme 1) required the preliminary synthesis of intermediate β-hydroxy-α-nitrosotherocycles 18 and 19 (Scheme 2) Important amounts of a coloured, non-photochromic, stable secondary product (See 20) were found in the condensation in the spiro[indole-thiazolobenzoxazine] series The photochromic characteristics of the new derivatives were determined using a flash-photolysis apparatus coupled to a fast-scanning spectrometer The role of the heteroatoms in the oxazine moiety and the role of substitutents in the indole moiety were investigated quantitatively through the study of the photochromic properties and the solvent effects The presence of an S-atom gives rise to interesting properties which open up new prospects for synthesis and application

Synthèse et propriétés photochromiques de 1, 3‐dihydrospiro[2H‐indole‐2,3′‐[3H]pyrimido[5,4‐f][1,4]benzoxazines] et de 1,3‐dihydrospiro[2H‐indole‐2,7′‐[7H]thiazolo[5,4‐f][1,4]benzoxazines]

Synthesis of novel coumarin and benzocoumarin derivatives and their biological and photophysical studies

Chapter 2 – Synthesis and photochromic properties of naphthopyrans

The product from the reaction of 2,2-diphenylchromen with a 1,1-diarylethylene has been shown by spectroscopic methods and by unambiguous synthesis to be a 2,2-diaryl-4-(2,2-diphenylvinyl)chroman. Similar reactions with related compounds have been carried out.

The reaction between 2,2-diarylchromens and 1,1-diarylethylenes

Reactions between 5,6-benzocoumarin and o-, m-, and p-methoxyphenylmagnesium bromides yield, inter alia, 1,3- and 3,3-bis(methoxyphenyl)naphtho[2,1-b]pyrans.

M. V. Walshaw

Papers

The reaction between 2,2-diarylchromens and 1,1-diarylethylenes

1,3- and 3,3-Bis(methoxyphenyl)naphtho[2,1-b]pyrans

Rk. zwischen 2,2-diaryl-chromenen und 1,1-diaryl-aethylenen

1,3- und 3,3-bis-(methoxyphenyl)-naphtho(2,1-b)pyrane