Tracing the wonders of oxygen using a novel microscope
The excited triplet in organic molecules can be quite long lived because the transition to the singlet ground state is optically forbidden. Nearby oxygen is known to quench the triplet state. Researchers at RUN have now succeeded in tracking this transfer of energy between a pentacene and an oxygen molecule directly in space. In the junction of an atomic force microscope they applied a sequence of fast electrical pulses to the pentacene molecule, driving it into the magnetic triplet state in a controlled fashion. The energy transfer from this excited triplet state to oxygen molecules nearby was then tracked in time by measuring miniscule changes in the force acting on the tip. By means of single-molecule manipulation techniques, different arrangements with oxygen molecules were created and characterized with atomic precision, allowing for the direct correlation of molecular arrangements with the lifetime of the quenched triplet.
The results have been published in Science.
Press release (idw) in German.
