Crystal Violet Lactone

Crystal violet lactone (CVL) is known as a leuco dye.
In a basic environment, the central carbon atom of crystal violet lactone (CVL) forms 4 covalent bonds and the molecule is colourless. In an acidic environment, the lactone ring is broken and the central carbon atom gains a positive charge through the loss of a valence electron, this is the coloured form of the molecule.
These reactions are shown below:

CVL was the first dye used in carbonless copy papers.
Carbonless paper consists of sheets of paper coated with a microencapsulated dye or a reactive clay.
The back of the first sheet is coated with the dye, the top of the lowest sheet is coated with a clay that quickly reacts with the dye to form a permanent mark. When you write on the sheets, the pressure of the pen tip breaks open the micor-capsules of dye, the dye reacts with the clay, and a permanent copy is made of the document.
Chemists in Poland have also discovered that CVL molecules emit white light with continuous spectrum covering almost the entire visible range. This is an important discovery because it is known that white light from artificial sources such as fluorescent lights is devoid of many colour components and that this is responsible for causing tired eyes. Making a better artificial white light could result in improved productivity in humans.

Reference:
Jerzy Karpiuk, Ewelina Karolak, Jacek Nowacki. Tuneable white fluorescence from intramolecular exciplexes. Physical Chemistry Chemical Physics, 2010; 12 (31): 8804 DOI: 10.1039/B927232A

Further Reading
http://www.ausetute.com.au/fungroup.html
http://www.ausetute.com.au/acidbase.html

Study Questions

1. Identify the various functional groups in each of the molecules shown above.
2. Name each of these functional groups.
3. Carefully read the introductory paragraph in the story above, and study the reaction diagram. Can you circle a lactone ring?
4. Imagine you could obtain pure samples of each of the two molecules shown. In what ways would the samples be similar? In what ways would they be different?
5. Describe two tests that you could used to distinguish between each of the pure samples above.