Current-Induced Hydrogen Tautomerization and Conductance Switching of Naphthalocyanine Molecules
Peter Liljeroth,1*
Jascha Repp,1,2
Gerhard Meyer1
The bistability in the position of the two hydrogen atoms in the inner cavity of single free-base naphthalocyanine molecules constitutes a two-level system that was manipulated and probed by low-temperature scanning tunneling microscopy. When adsorbed on an ultrathin insulating film, the molecules can be switched in a controlled fashion between the two states by excitation induced by the inelastic tunneling current. The tautomerization reaction can be probed by resonant tunneling through the molecule and is expressed as considerable changes in the conductivity of the molecule. We also demonstrated a coupling of the switching process so that the charge injection in one molecule induced tautomerization in an adjacent molecule.
1 IBM Zurich Research Laboratory, 8803 Rüschlikon, Switzerland.
2 Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany.
* To whom correspondence should be addressed. E-mail: pli{at}zurich.ibm.com
