Efficient conducting channels
[2,2]paracyclophane molecules
formed
by
the
π-π
stacking
in
single
Meilin Bai1, Jinghong Liang2, Liqiang Xie2, Stefano Sanvito3, Bingwei Mao2, Shimin
Hou1,*
1
Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Elec-
tronics, Peking University, Beijing 100871, China
2
State Key Laboratory of Physical Chemistry of Solid Surfaces and College of
Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
3
School of Physics and CRANN, Trinity College, Dublin 2, Ireland
1. The atomic structure and the frontier molecular orbitals of [3,3]paracyclophane in the
trans form
(a)
(b)
Fig. S1 The optimized atomic structure (a) and the frontier molecular orbitals ranging
from the HOMO-3 to the LUMO+3 (b) of trans [3,3]paracyclophane
-1-
2. The atomic structure and the frontier molecular orbitals of [4,4]paracyclophane in the
trans form
(a)
(b)
Fig. S2 The optimized atomic structure (a) and the frontier molecular orbitals ranging
from the HOMO-3 to the LUMO+3 (b) of trans [4,4]paracyclophane
3. The atomic structure of the asymmetric Au-[2,2]paracyclophane-Au junction
Fig. S3 The optimized atomic structure of the asymmetric Au-[2,2]paracyclophane-Au
junction
-2-
4. The equilibrium transmission spectrum of the symmetric Pt-[3,3]paracyclophane-Pt
junction
Fig. S4 The equilibrium transmission spectrum of the symmetric Pt-[3,3]paracyclophanePt junction
5. The conductance measurement of platinum electrodes in pure tetradecane
4
Counts
G / G0
3
2
1
0
0.0
0.4
0.8
1.2
1.6
0
1
2
3
4
G / G0
Distance / nm
(a)
(b)
Fig. S5 Individual conductance traces (a) and the corresponding conductance histogram
constructed from 256 traces without data selection (b) for platinum electrodes in pure
tetradecane. The conductance peak near 1.0 G0 is consistent with the references [S1, S2]
-3-
6. The atomic structures and equilibrium transmission spectra of asymmetric Pt[2,2]paracyclophane-Pt junctions
(a)
(b)
(c)
(d)
Fig. S6 The optimized atomic structure (a) and the equilibrium transmission spectrum (b)
of an asymmetric Pt-[2,2]paracyclophane-Pt junction, in which the [2,2]paracyclophane
molecule is connected to one Pt electrode through one Pt adatom and to the other Pt
electrode through a Pt4 cluster in the pyramid form. When one Pt atom is added near the
Pt adatom on the surface of the right electrode (c), the transmission is further decreased
(d).
-4-
7. Parameters of the Gaussian fitting used in Fig. 6
The Gaussian fitting used in Fig. 6 is based on the following fitting equation:

A
y  y0 
w

e
2( x  x0 )2
w2
2
Here, y0 is the baseline offset, A is the total area under the curve from the baseline, x0 is
the center of the peak, and w is proportional to the width of the peak at half height.
Table S1 Parameters of the Gaussian fitting used in Fig. 6
Peak 1
x0
w
Fig. 6(b) 0.0075 0.0045
Fig. 6(d) 0.4
0.3
Peak 2
x0
w
0.95 0.4
References
[S1] Ko, C.; Huang, M.; Fu, M.; Chen, C. Superior Contact for Single-Molecule
Conductance: Electronic Coupling of Thiolate and Isothiocyanate on Pt, Pd, and Au. J.
Am. Chem. Soc. 2009, 132, 756-764
[S2] Olesen, L.; Laegsgaard, E.; Stensgaard, I.; Besenbacher, F.; Schiøtz, J.; Stoltze, P.;
Jacobsen, K. W.; Norskøv, J. K. Quantized Conductance in an Atom-Sized Point Contact.
Phys. Rev. Lett. 1994, 72, 2251-2254
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