Guest lecture - Prof. Dr. Josef Michl

University of Colorado, Boulder - "Metalloporphenes, a New Family of Conjugated 2-Dimensional Polymers”⠀

Two-dimensional materials have unusual properties and promise applications in nanoelectronics, spintronics, photonics, etc. Most are inorganic and their properties are difficult to tune. We have prepared Zn porphene, a fully conjugated two-dimensional organic polymers composed of fused porphyrin rings, by oxidative polymerization of a Langmuir bilayer of Zn porphyrin on water surface. It is transferable to other substrates and bridges µm-sized pits. Contrary to previous theoretical predictions, it is a p-type semiconductor due to a distortion of its unit cell from square to rectangular shape, analogous to the appearance of bond-length alternation in antiaromatic molecules. Reversible insertion of metal ions, possibly with a fifth or sixth ligand, promises patterning circuits on an atomic canvas without removing any π centers from conjugation.