There are several compounds, that has a near no emission under UV light at room temperature, but when it’s cooled down with liquid nitrogen, the emission increases a lot. This phenomena is called low temperature fluorescence thermochromism.



In this case I prepared an organic compound what is a white crystalline solid at room temperature, but when it is cooled below -100 °C it emits a bright blue light when exposed to UV light.



While being irradiated with UV light, as temperature drops in the flask and the crystals reach a specific temperature, they start to emit light. It’s a quite adorable thing, since you can actually see the temperature.

How does it work? Depending on the temperature the bonds in these molecules change a lot what means they can absorb and emit different wavelength. When irradiated with UV light at room temperature, the compound emits some visible light, but when it is cooled down with liquid nitrogen the compound emits a different wavelength light with a different intensity.

9:30 pm • 31 July 2016 • 400 notes • View comments