What is it about?

This paper reports on how the intensity and responsivity of a particularly important type of photochromic dye can readily be manipulated by altering the structure of one part of the molecule. There are relatively little data published on the subject in the academic literature despite these types of dye being commercially useful.

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Why is it important?

There are many studies that employ these kinds of photochromic dye in investigations in a wide range of fields, from biomedicine to information technology. However, the academics performing these studies appear to know relatively little of dye design in relation to photochromic properties. Numerous investigations therefore abandon usage of the type of dye discussed in this paper because their design meant that their response to light was relatively weak. However, if such studies had utilised dyes incorporating the kinds of structural modifications to enhance responsivity described here, then better results may have been obtained.


I worked on the research and development of photochromic materials during my fifteen years as an employee of James Robinson Ltd / Vivimed Labs Ltd. This included discovering new colorant molecules, improving existing processes to their manufacture or devising new ones, and producing photochromic dyes (plus their intermediates} at the kilo scale for sale across the world. The complexity of the synthesis and design of these materials is not widely appreciated.

Dr Andrew D Towns

Read the Original

This page is a summary of: Photochromism in spiroindolinonaphthoxazine dyes: Effects of alkyl and ester substituents on photochromic properties, Dyes and Pigments, May 2014, Elsevier, DOI: 10.1016/j.dyepig.2014.01.005.
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