page_title: Klaus Müllen
section_title: Research career
hierarchical_section_title: Klaus Müllen / Research career
context_page_description: Klaus Müllen is a German chemist working in the fields of polymer chemistry, supramolecular chemistry and nanotechnology. He is known for the synthesis and exploration of the properties of graphene-like nanostructures and their potential applications in organic electronics.
context_section_description: In 1979 he became professor of organic chemistry at the University of Cologne, in 1983 he went to the University of Mainz as a professor. Since 1989 he has been director and scientific member of the Max Planck Institute for Polymer Research. In 2016 he became emeritus. Since 1995 he has been honorary professor at the University of Mainz and at the Gutenberg Research College of the University of Mainz. He is an Associate Editor of the Journal of the American Chemical Society
  His research interests are in the field of preparative macro- and supramolecular chemistry. Among other things, his group has succeeded in synthesizing and characterizing hitherto unattainable large polycyclic aromatics such as superphenalene, which has a molecular mass of 1182 g·mol⁻¹ and consists of 34 condensed benzene rings. 
   
  He has developed small disc-like organic building blocks using alkyl-substituted hexabenzocoronene, and in particular HBC-C12 - which self-assembles into crystalline liquid-phase structures (columnar liquid crystals) as potential organic field-effect transistors. The considered two-dimensional benzene ring structures are examples of subunits of graphene lattices (graphene nanostructures). The graphene-like structures synthesized and investigated by Müllen include two-dimensional bands of less than 50 nanometers width with jagged edges. Of interest here are the electronic conduction properties and spintronics properties with a view to future replacement of silicon-semiconductor technology.  In synthesis, he introduced a new method in graphene polymer chemistry: soft-landing mass spectrometry.  Applications include synthetic light-emitting organic materials (such as OLEDs) and incorporation of molecular defects (defect engineering) organic analogues of semiconductor technology.
caption: Structure of superphenalene