Cross-Conjugation and Quantum Interference

As nanoscience develops, so do the physical measurements we perform, and the types of environments under which we consider molecular properties. One consequence of this development is that classes of systems that are well known and studied in one field can suddenly ignite interest in another. While the result might not surprise in retrospect, it certainly could not have been predicted. This has certainly been the case for cross-conjugated molecules in molecular electronics. This monograph testifies the breadth of this class of compounds and the wide range of their applicability. But it is unlikely that any synthetic chemist, no matter how expert, would have predicted that these systems would become the poster children for quantum interference in electron transport. 

The interest in interference effects in cross-conjugated molecules arose from molecular electronics. The chemist s vision of molecular electronics consists of chemically tailored circuits, where the electronic function is controlled by carefully designed substituents. This requires more than molecular wires it requires functions such as memory elements, switches, logic elements, and gate dielectrics. In short, it requires polarizable but nonconducting elements. In many of these cases, an ofT state is required in addition to the on state. Sometimes there is a requirement for fast switching between these states, and at other times long-term stability of either the on or oflT state is needed. 

Cross-conjugation makes this possible as it results in interference effects that deliver an ofT state in fully conjugated systems. 

This chapter begins with an introduction to electron transport in organic molecules and how to understand the measurements/calculations. Next, we explore how to understand and predict interference effects and, finally, we go beyond topology and explain how interference effects can be controlled chemically. 

Cross Conjugation Dendralene, Radialene and Fulvene Chemistry, First Edition. 

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Cross-Conjugation and Quantum Interference Electron withdrawing... 

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