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.
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
