https://doi.org/10.1351/goldbook.HT07392
Applied to @[email protected] compounds possessing a high efficiency for colouring with [email protected]@ radiation and a low efficiency for @[email protected] with @[email protected] radiation, but a moderate efficiency for thermal fading at ambient temperature. These compounds are activated by unfiltered sunlight and deactivated under diffuse daylight conditions, therefore being suitable for sun-lens applications.