3,3-Diphenyl-3H-naphthopyran
Chemical compound
From Wikipedia, the free encyclopedia
3,3-Diphenyl-3H-naphthopyran is an organic compound that is the parent of several related naphthopyrans. This family of compounds are used as photochromic dyes in ophthalmic glasses.[1] The compound is a colorless solid.
| Names | |
|---|---|
| Preferred IUPAC name
3,3-Diphenyl-3H-naphtho[2,1-b]pyran | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.111.746 |
| EC Number |
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PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| C25H18O | |
| Molar mass | 334.418 g·mol−1 |
| Appearance | colorless solid |
| Melting point | 158–160 °C (316–320 °F; 431–433 K) |
| Hazards | |
| GHS labelling: | |
| Warning | |
| H411 | |
| P273, P391, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and reactions
The synthesis of naphthopyrans starts with 2-naphthol.[2]
Upon exposure to UV-radiation, the pyran ring opens. The products, "photomerocyanines", are yellow to red dark colored.[3]

