Chemistry Reference
In-Depth Information
Fig. 10.7 a Side view of the H
2
O-(OH)
2
chain optimized by DFT calculations b STM images of
the H
2
O-(OH)
2
chain and its counterpart superimposed with the lattice of Cu(110) (white lines).
The appearance can be inverted by the voltage pulse of STM over the protrusion. The inversion
was also observed for (c)H
2
O-(OH)
3
and (d)H
2
O-(OH)
4
chains. The dots in (b-d) indicate the
nearest short-bridge sites binding oxygen atoms in the chains (note that oxygen atom positions
deviate from the exact short-bridge sites as shown in Fig.
10.6
a). The inversion of the appearance
corresponds to H-atom relay reaction in which a sequential H-atom transfer is included as shown
by curved arrows in (a).The images were obtained at V
s
= 24 mV and I
t
= 0.5 nA (18 9 29 Å
2
).
The range of the height shown in the color scale is from -0.36 to 0.44 Å
yield is the largest when the tip is positioned over the water molecule, but at
V
s
= 443 mV it is more broadly distributed over the chain, indicating that dif-
ferent vibrational modes are involved at these different voltages.
