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Extended curly arrow rules to rationalise and predict structural effects on quantum interference in molecular
Luke J O'Driscoll1, Martin R Bryce1
1Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham, DH1 3LE, UK. m.r.bryce@durham.ac.uk.
Nanoscale
|January 4, 2021
Summary
Predicting quantum interference (QI) in molecular wires is crucial for designing electronic devices. Extended curly arrow rules (ECARs) offer a simple method to forecast QI behavior in complex molecular structures.
Area of Science:
- Quantum Chemistry
- Materials Science
- Molecular Electronics
Background:
- Predicting quantum interference (QI) is vital for designing molecular wires used in switches, transistors, and thermoelectric devices.
- Existing predictive methods often fail for molecules with complex structures, unlike computationally intensive DFT simulations.
Purpose of the Study:
- To develop an accessible predictive method for quantum interference (QI) in diverse molecular wire structures.
- To extend existing
- curly arrow rules
- to accurately predict QI behavior.
Main Methods:
- Developed an extension to predictive "curly arrow rules", termed extended curly arrow rules (ECARs).
- Applied ECARs to rationalize QI in conjugated molecular wires with heteroatoms, cross-conjugation, and non-alternant structures.
Main Results:
- ECARs successfully rationalize the type of QI (constructive, destructive, or shifted destructive) in most tested molecular wires.
- The method predicts the presence and energy of antiresonances in the transmission function.
Conclusions:
- ECARs provide a straightforward "pen-and-paper" approach for predicting QI in molecular wires.
- This method enhances the design of functional molecular wires by reliably predicting their electronic properties.
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