Synthesis of Tridecacene by Multistep Single-Molecule Manipulation

Area of Science:

• Materials Science
• Organic Chemistry
• Surface Science

Background:

• Acenes are crucial polycyclic aromatic hydrocarbons for organic electronics.
• Synthesizing longer acenes is key to understanding their properties.
• Previous work achieved up to dodecacene, necessitating further expansion.

Purpose of the Study:

• To synthesize and characterize tridecacene, a novel long acene.
• To investigate the electronic properties of tridecacene, particularly its ground state and transport gap.
• To understand the influence of the Au(111) surface on tridecacene's properties.

Main Methods:

• On-surface synthesis using atom-manipulation on a Au(111) surface.
• Scanning tunneling microscopy and spectroscopy (STM/STS) for characterization.
• First-principles calculations, including spin-polarized density functional theory.

Main Results:

• Successful synthesis of tridecacene.
• Observed a transport gap of 1.09 eV, showing a non-monotonous trend with length.
• Calculations revealed an open-shell antiferromagnetic ground state in gas phase, significantly altered by surface physisorption.
• Surface interaction reduced tridecacene's spin polarization and HOMO-LUMO gap.

Conclusions:

• Tridecacene exhibits unique electronic properties influenced by surface interactions.
• The Au(111) substrate significantly modifies the electronic structure of long acenes.
• Findings contribute to understanding length-dependent electronic properties and developing synthesis techniques for advanced organic materials.