On-Surface Synthesis of Electron- Deficient Bisanthene Tetraimide

Imide-based conjugated molecules have emerged as a highly promising class of building blocks for con-structing n-type semiconducting materials with low-lying lowest unoccupied molecular orbitals and exceptional stability. Although imides, such as naphthalene diimides, perylene diimides and their lateral fused analogs, have been synthesized extensively, the design and synthesis of larger pi-extended molecules incorporating more than two imide groups are desirable but still very challenging. Herein, we report the synthesis of an unprecedented electron-deficient bisanthene tetraimide (ATI) containing a bisanthene-conjugated core and four five-membered imide groups, which was successfully achieved via a com-bined approach of solution and on-surface synthesis. The chemical structures, electronic states, formation mechanism and aromaticity of ATI were systemati-cally investigated by scanning tunneling microscopy, noncontact atomic force microscopy, scanning tunneling spectroscopy, and density functional the-ory calculations.