Brief Analysis of the Different Chapters and their Main Topics

BRIEF ANALYSIS OF THE DIFFERENT CHAPTERS AND THEIR MAIN TOPICS 

Chapter 1 (Spiropyrans) covers the most intensively studied families of photochromic compounds. 

This chapter, with over 200 references, is an extensive survey of the photochromic molecular and supramolecular systems involving the spiropyran entity. It also serves as an excellent introduction for the individual who does not have a comprehensive understanding of the phenomenon of photochromism. 

Chapter 3 (Benzo and naphthopyrans or chromenes). This chapter reviews another important type of thermoreversible photochromic compounds that have found application in the variable optical transmission materials field, specifically, 

Their resistance to photooxidation is also good relative to most other families of photochromic compounds. In this property they are comparable to the spirooxazines, which again adds to the complementary character of the two families. The color of the open forms can be tuned over a large range of the visible spectrum, by substituents on the naphthyl moiety or on the aromatic groups present on the sp3 carbon atom of the pyran ring. 

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