The innovation engine for new materials

Mark Johnson

Mark Johnson


Chemistry and Physics


University of Connecticut


Angelique Scheuermann

Faculty Sponsor(s): 

Javier Read de Alaniz

Faculty Sponsor's Department(s): 

Chemistry and Biochemistry

Project Title: 

Synthesis of a Light-responsive Diarylethene Catalyst for Remoldable Materials

Project Description: 

Robust materials such as car tires and foam cushions are unable to be recycled due to their cross-linked polymeric networks. Recently, novel materials known as vitrimers have been synthesized to provide similar robust mechanical properties while also being remoldable. Vitrimers are normally activated in response to heat, but light would provide greater spatial and temporal control over the material. We propose to utilize a light-responsive catalyst based on a diarylethene photoswitch to render vitrimeric materials light-responsive. Diarylethene photoswitches can change their electronic structure when exposed to specific wavelengths of light. Our chosen diarylethene photoswitch, which contains an N-heterocyclic carbene, acts as a transesterification catalyst under visible light and is inactive under UV light. Air-free Schlenk line techniques, column chromatography, and 1H NMR spectroscopy were employed to purify and characterize the intermediates along the eight-step synthetic route. We found that reactions in this eight-step synthesis could be safely performed in multigram scales. The catalytic activity of the diarylethene catalyst will be examined using 1H NMR model studies of transesterification reactions before being employed in vitrimeric materials.