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A Trapezoidal Octacyanoquinoid Acceptor Forms Solution and Surface Products by Antiparallel Shape Fitting with
Samara Medina Rivero1, Javier Urieta-Mora2,3, Agustín Molina-Ontoria2
1Department of Physical Chemistry, University of Málaga, Andalucia-Tech Campus de Teatinos s/n, 29071, Málaga, Spain.
Angewandte Chemie (International Ed. in English)
|June 4, 2021
Summary
A novel tetracyano thienoquinoidal compound self-assembles into a dense 2D layer on gold surfaces. Its unique charge distribution and conformational changes enable specific surface interactions and molecular dipole formation.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Electrochemistry
Background:
- Thienoquinoidal compounds are of interest for their electronic properties.
- Controlling molecular self-assembly on surfaces is crucial for advanced materials.
Purpose of the Study:
- To synthesize and characterize a new tetracyano thienoquinoidal compound.
- To investigate its self-assembly behavior on a gold surface.
- To understand the electronic and structural properties of the compound and its assembly.
Main Methods:
- Synthesis of the new compound (1).
- Electrochemical studies, UV/Vis-NIR, IR, and EPR spectroscopy.
- Transient spectroscopy for dynamic behavior analysis.
- Scanning tunneling microscopy (STM) for surface self-assembly investigation.
- Quantum chemical calculations for experimental data rationalization.
Main Results:
- The new compound (1) was successfully synthesized.
- Electrochemical and spectroscopic studies revealed unique charge distribution in its anionic form.
- STM demonstrated the formation of a dense, ordered 2D assembly of 1 on Au(111).
- Quantum chemical calculations supported the experimental findings, explaining charge distribution and conformational changes.
- A molecular in-plane electric dipole transforms out-of-plane upon surface deposition due to conformational change and charge transfer.
Conclusions:
- The synthesized tetracyano thienoquinoidal compound exhibits tunable electronic properties.
- The compound self-assembles effectively on Au(111) via van der Waals interactions and shape complementarity.
- Surface deposition induces conformational changes and charge transfer, leading to out-of-plane dipole formation.
- This study provides insights into designing functional molecular assemblies on surfaces.
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