Single-Molecule Conductance in a Series of Extended Viologen Molecules.
Single-molecule conductance in a series of extended viologen molecules was measured at room temperature using a gold-molecule-gold scanning tunneling microscopy break junction arrangement. Conductance values for individual molecules change from 4.8 ± 1.2 nS for the shortest compound to 2.9 ± 1.0 nS for the compound with six repeating units and length of 11 nm. The latter value is almost 3 orders of magnitude higher than that reported for all-carbon-based aromatic molecular wires of comparable length. On the basis of the length of the molecules, an attenuation factor of only 0.06 ± 0.004 nm(-1) (0.006 ± 0.0004 Å(-1)) was obtained. To the best of our knowledge, this is the smallest value reported for the conductance attenuation in a series of molecular wires.
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.
Viliam
V
Kolivoška
‡Institute of Organic Chemistry and Biochemistry of ASCR, v.v.i., Flemingovo n. 2, 16610 Prague, Czech Republic.
Michal
M
Valášek
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.
Miroslav
M
Gál
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.
Romana
R
Sokolová
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.
Jana
J
Bulíčková
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.|‡Institute of Organic Chemistry and Biochemistry of ASCR, v.v.i., Flemingovo n. 2, 16610 Prague, Czech Republic.
Lubomír
L
Pospíšil
§Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Pusztaszeri strasse 59-67, H-1025 Budapest, Hungary.
Gábor
G
Mészáros
†J. Heyrovský Institute of Physical Chemistry of ASCR, v.v.i., Dolejškova 3, 18223 Prague, Czech Republic.
Magdaléna
M
Hromadová
electron transfer; extended viologens; molecular wires; scanning tunneling microscopy break junction; single molecule conductance