Conjugated Ladder Polymers by a Cyclopentannulation Polymerization

Abstract

We report a nontraditional synthesis of cyclopentafused-polycyclic aromatic hydrocarbon embedded ladder polymers using a palladium catalyzed cyclopentannulation polymerization followed by a cyclodehydrogenation reaction. Donor-acceptor type polymers containing a cyclopenta[hi]aceanthrylene acceptor groups can be synthesized by a palladium catalyzed copolymerization between 9,10-dibromoanthracene and a variety of bis(arylethynyl)arenes to give polymers with molecular weights (Mn) of 9-22 kDa. The bis(arylethynyl)arenes were composed of benzene, thiophene, or thieno[3,2-b]thiophene moieties, which provided access to a series of four donor-acceptor copolymers. The polymers were subjected to cyclodehydrogenation with FeCl to access rigid ladder type polymers with the conversion investigated by C NMR of isotopically labeled polymers. The ladder polymers possess broad UV-Vis absorptions and narrow optical band gaps of 1.17-1.29 eV and are p-type semiconductors in organic field effect transistors.

Layered Thiadiazoloquinoxaline‐Containing Long Pyrene‐Fused N‐Heteroacenes

“…The conjugation length of NHAs strongly affects the electronic distribution, the stability, as well as electronic properties . Although the synthesis of long NHAs is tedious and challenging, numerous efforts have contributed to the exploration of large NHAs in the past decade . Owing to the poor solubility and low stability of extended NHAs, studies on their packing and charge transport are still rare today.…”

Emerging Bottom‐Up Strategies for the Synthesis of Graphene Nanoribbons and Related Structures

“…Plunkett and co-workers reported the synthesis of al adder polymer whose structure is very similar to aG NR, but includes five-membered ring, providing an ew set of optoelectronic properties (20,S cheme 4). [78] Thes ynthesis of the polymeric precursor proceeds through apalladium-catalyzed pentannulation reaction between 9,10-dibromoanthracene 17 and the bis(alkyne) 18.S imilar to Dichtelsw ork, the cyclopentannulation reaction was used to prepare aprecursor that have to be subjected to the Scholl reaction to give afully aromatized GNR.…”

Polycyclic Aromatic Hydrocarbons as Potential Building Blocks for Organic Solar Cells

“…Conjugated ladder cyclopenta[ hi ]aceanthrylene‐based polymers (ex. 42 , Figure ) have also been obtained by cyclopentannulation between 9,10‐dibromoanthracene and 1,4‐bis((3‐((2‐decyltetradecyl)‐oxy)phenyl)ethynyl)benzene, followed by a dehydrogenation (Scholl) reaction . The planarization of the conjugated backbone yielded to the lowest band gap value (E g =1.17 eV) ever reported for a cyclopenta[ hi ]aceanthrylene‐based polymer.…”