Extended aromatic system gives new dyes

A new class of compounds for making yellow and violet dyes has been discovered by chemists in Germany. 

Klaus Müllen’s group, from the Max-Planck Institute for Polymer Research in Mainz, found that by simply enlarging the aromatic π-system of a well known red perylene carboximide core, they could make two new chromophores.  

The change in the absorption shifts, caused by the extended π-system, made the chromophores appear bright yellow and violet. 

In future, Müllen hopes to apply his ideas to other polycyclic aromatic hydrocarbons, especially higher homologs of perylene, to allow him to tune dye properties.  

Müllen expects to find applications for the chromophores as new stable yellow pigments, as violet dyes and pigments, in laser welding and in optoelectronic devices. To do this, absorption and emission must be carefully controlled, and the functional dyes, as active components in electronics and optoelectronics devices, must have high chemical stability and photostability. 

Elinor Richards