Carbene dye is a reactive dye based on carbene chemistry. A carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons which make it more reactive.
How it works?
A benzophenone is functionalized with a reactive group that can be easily converted to a chromophore at a later stage. The functionalized benzophenone is reacted with hydrazine hydrate and subsequently treatment with mercury oxide. The resulting diazo compound is stable at room temperature. On heating, nitrogen gas is released and the carbene generated. The generated carbene reacts rapidly with substrates such as nylon, cotton, glass and polyethylene.
The highly reactive carbene group removes the need for different functional groups depending on the substrate to be dyed. For example a dye that can color cotton would usually not be appropriate for dyeing polyethylene, but by using a carbene, the same dye can be used for both.
