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Chiral Recognition of 4,4’ Biphenyl Dicarboxylic Acid (BPDA) on
fcc(111) Surfaces in Electrochemical Solutions
Byung I. Kim, Department of Physics, Boise State University, Boise, Idaho 83725
The goal of this project is to understand the
influence of “molecular symmetry” of the
composite structure of 4,4’ Biphenyl Dicarboxylic
Acid (BPDA) /fcc(111) on the organic chiral
recognition in the electrochemical environment.
We investigated the influence by observing the
structural configurations of BPDA molecules on
two different substrates, Au(111) and Pd(111), in
the perchloric (HClO4) acid by the electrochemical
scanning tunneling microscopy (EC-STM).
a
BPDA/fcc(111)
R
Au(111)
P
CB
ri,
BPDA/fcc(111)
Pd(111)
BPDA/Au(111)
(15 nm x 15 nm)
BPDA/Pd(111)
(46 nm x 46 nm)
The EC-STM images show that BPDA
molecules form Self-assembled
hydrogen bond networks on both
Au(111) and Pd(111). However, they
showed different orientational ordering
and packing density between Au(111)
and Pd(111), indicating different
recognition of BPDA molecules on the
two different substrates. The
theoretical model calculation suggests
that the substrate dependent organic
chiral recognition results from different
substrate-adsorbate interactions
between Au(111) and Pd(111).