My watch list
my.chemeurope.com  
Login  

Flexible tapes from the nanoworld

Chemical reaction yields "tapes" of porphin molecules

14-Aug-2014

W. Auwärter/Alissa Wiengarten/TUM

Porphin-Dimere

Thorsten Naeser/Munich-Centre for Advanced Photonics

Alissa Wiengarten, PhD student at the TUM Department of Physics, heats a porphine powder in a vacuum chamber.

Dr. Wilhelm Auwärter and his team are working on a research project to develop tiny flat molecule tapes at the Department of Physics of Technische Universität München (TUM). These structures could find versatile applications. Via direct coupling on a silver surface, the scientists successfully formed dimers and short chains of porphine molecules without contaminating by-products.

Porphyrin molecules are essential to many biological processes, such as photosynthesis and respiration.Dr. Wilhelm Auwärter'sgroup is investigating these all-round talents at TU München. Normally, hydrogen attaches to the outer edges of the porphyrin core – named porphine, but other chemical entities can take the place of hydrogen, thereby changing the properties of the molecules.

Alissa Wiengarten, PhD student at the TUM Department of Physics, heats a porphine powder in a vacuum chamber. In the process, individual porphine molecules leave the collective and adhere to a silver surface, where they react with each other and assemble into small groups – all by themselves. Single molecules can desorb from the hot surface, while chains of two, three or more porphine units cannot. In this way the scientists were able to assemble chains of up to 90 porphine units.

Thorough analysis

Using a surface made of silver is essential to the experiment: "Silver seems to be a kind of catalyst for the reaction", Wilhelm Auwärter explains. "Still, we don't fully understand why this is the case."

Aside from fundamental questions, Auwärter’s group also hopes to find a way to generate ordered long molecular porphin chains, so-called tapes. Only one molecule wide, such structures could serve as optically active elements in electronic applications or data storage. 

In order to investigate these tiny structures on the silver surface, Auwärter's team uses a whole range of sophisticated structure analysis techniques available at TUM and through cooperation with international partners.

Fascinating images of the molecular structures, for example, were captured using a scanning tunneling microscope at TUM. The team also conducted spectroscopy analyses using synchrotron radiation of the ELETTRA storage ring in Trieste, which provided important insights into the electronic structure of the porphine groups.

Facts, background information, dossiers
  • porphin
More about TU München
  • News

    Climate-friendly architecture thanks to natural folding mechanisms

    Mobile components on buildings such as blinds whose design was copied from naturally occurring solutions -- that is the subject of the research conducted by a team from the Technical University of Munich (TUM), the University of Freiburg, and the University of Stuttgart. The aim is to outfi ... more

    Electrode materials from the microwave oven

    Power on the go is in demand: The higher the battery capacity, the larger the range of electric cars and the longer the operating time of cell phones and laptops. Dr. Jennifer Ludwig of the Technical University of Munich (TUM) has developed a process that allows a fast, simple, and cost-eff ... more

    Chemical hotspots

    Chemistry live: Using a scanning tunneling microscope, researchers at the Technical University of Munich (TUM) were able for the very first time to witness in detail the activity of catalysts during an electro-chemical reaction. The measurements show how the surface structure of the catalys ... more

  • Videos

    Scientists pair up two stars from the world of chemistry

    Many scientists consider graphene to be a wonder material. Now, a team of researchers at the Technical University of Munich (TUM) has succeeded in linking graphene with another important chemical group, the porphyrins. These new hybrid structures could also be used in the field of molecular ... more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE