Articolo in rivista, 2021, ENG, 10.1039/d1ra03253d

On-surface synthesis of ?-conjugated ladder-type polymers comprising nonbenzenoid moieties

Urgel, José I.; Bock, Julian; Di Giovannantonio, Marco; Ruffieux, Pascal; Pignedoli, Carlo A.; Kivala, Milan; Fasel, Roman

University of Bern; Empa - Swiss Federal Laboratories for Materials Science and Technology; Universität Heidelberg

On-surface synthesis provides a powerful approach toward the atomically precise fabrication of ?-conjugated ladder polymers (CLPs). We report herein the surface-assisted synthesis of nonbenzenoid CLPs from cyclopenta-annulated anthracene monomers on Au(111) under ultrahigh vacuum conditions. Successive thermal annealing steps reveal the dehalogenative homocoupling to yield an intermediate 1D polymer and the subsequent cyclodehydrogenation to form the fully conjugated ladder polymer. Notably, neighbouring monomers may fuse in two different ways, resulting in six- and five-membered rings, respectively. The structure and electronic properties of the reaction products have been investigatedvialow-temperature scanning tunneling microscopy and spectroscopy, complemented by density-functional theory calculations. Our results provide perspectives for the on-surface synthesis of nonbenzenoid CLPs with the potential to be used for organic electronic devices.

RSC advances 11 (38), pp. 23437–23441

Keywords

Ladder polymers, stm, sts, on-surface synthesis

CNR authors

Di Giovannantonio Marco

CNR institutes