Module 4 – Molecular Electronics
Molecular Electronics combines Nanoelectronics and Nanoelectrooptics with Synthetic Supramolecular
Chemistry. All projects within the module are strongly interrelated. They cover the following topics:
- molecular wires
- transport properties and networks of molecular junctions
- optical properties and electron spectroscopy of single molecules
- chemical synthesis of novel conjugated molecules for electrooptical applications
By studying single supramolecular structures and the way they conduct current, we can learn a great deal
about the way electrons flow through molecules and about single-molecule functions.
The rational design and preparation of molecular (nano-) systems are the challenges of modern synthetic
chemistry. As a consequence of the intense interest in this field, the synthetic methodologies are nowadays
prepared to approach a variety of nano-sized molecular systems with specific functionalities. Such tailored
molecules are used within this NCCR project in:
- surface assembling studies (STM imaging and spectroscopy)
- optical studies
- single-molecule experiments (single-molecule electrical transport)
- studies of assembled networks.
Theory is going to address fundamental aspects of molecular charge transport.
A selection of key questions are:
Can we find molecular switches and memory elements that have a high on-off ratio and that can be built
from molecules in a reliable and reproducible way? Is it possible to achieve a large transmission
probability approaching unity in molecules? Is it possible to go beyond single molecule junctions and
to build networks of junctions with a multitude of embedded functions?
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Possible mechanisms for reversible molecular switches.
(a) Electrochemically controlled desorbtion of an anchoring group (triangle).
This can be envisioned for molecules with two distinct anchoring groups, e.g.: z.B. -SH (●) und
–CN (▶).
(b) Electrochemically induced switching. The controlled charging of a redox active unit can induce a
conductance change.
(c) Light-induced switching. UV light will drive the system from open to closed, while visible light will
drive the transition from closed to open.
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Redox switchable TTF derivative. |
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Light-switchable 1,2-bis-(3-thienyl)ethane derivative. |
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