Engineered organically: specialized compounds for tomorrow's electronic devices

In a groundbreaking development, researchers from Empa's "nanotech@surfaces" laboratory and the Max Planck Institute for Polymer Research have successfully integrated organic porphyrin molecules with functional metal centers into a graphene nanoribbon with atomic precision. This hybrid system, published in the journal "Nature Chemistry", promises exciting possibilities for molecular electronics.

Porphyrins, a specific group of chemical structures that form an organic ring, are the basis for hemoglobin, chlorophyll, and numerous enzymes. The flexibility and functionality of these molecules have long been of interest to chemists and materials scientists due to their potential applications in molecular electronics.

The resulting compound from the porphyrin molecules and metal centers exhibits different chemical and physical properties depending on the metal trapped in the porphyrin. The metal atoms in the porphyrin molecules are held in place by four nitrogen atoms and are magnetically "conventional".

The graphene nanoribbon, a long, narrow strip of two-dimensional carbon material with unique physical properties depending on its width and edge shape, acts as a connector for the porphyrin molecules, each containing a metal center. The graphene band acts as an electrical and magnetic conductor, a kind of nanoscale "cable" between the porphyrin molecules.

The unique type of magnetism exhibited by the graphene nanoribbon due to its zigzag edge, combined with the magnetism of the porphyrin molecules, allows for the combination and connection of both types of magnetism in one system. This coupling enables applications in molecular electronics.

Moreover, the porphyrins are optically active, meaning they can emit light whose wavelength changes with the magnetic state of the entire molecular system. This property could potentially be used for sensor applications.

Empa researchers used a one-nanometer wide graphene ribbon with zigzag edges as a molecular wire for the porphyrin molecules. The precision with which these molecules have been coupled to the graphene nanoribbon opens up new possibilities for the development of advanced molecular devices.

Organic chemistry is the basis of all life on Earth and plays a key role in many biochemical processes, with metals also playing a significant role. The integration of these two elements—organic porphyrins and graphene—could pave the way for future advancements in the field of molecular electronics.

In conclusion, the study on this research represents a significant step forward in the integration of organic molecules with graphene for potential applications in molecular electronics. The magnetically and electronically coupled hybrid system offers exciting possibilities for the development of new sensors and devices.