1,1′-Biaceanthrylene and 2,2′-Biaceanthrylene: Models for Linking Larger Polycyclic Aromatic Hydrocarbons via Five-Membered Rings

Abstract

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two fivemembered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2′biaceanthrylene) or inward (1,1′-biaceanthrylene), and the optical and electronic properties were compared. Only the planar 2,2′-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer. Organic field effect transistors based on 2,2′-biaceanthrylene were prepared and were found to operate in the hole transport regime with an average charge carrier mobilities of 1.8 × 10 −4 cm 2 V −1 s −1 .

Bis-benzofulvenes: Synthesis and Studies on Their Optoelectronic Properties

“…Subjecting compound 2a under dimerization conditions using a stoichiometric amount of Ni(COD) 2 with a bipy ligand in tetrahydrofuran (THF) at 65 °C provided the desired bis-benzofulvene 3a as a bright orange solid in 51% yield (44% at a 1 mmol scale; Table 2). 18 Applying this dimerization strategy to other bromobenzofulvene esters 2b− 2f resulted in the corresponding bis-benzofulvene esters 3b−3f in good yields (47−76%). Bromobenzofulvene amides (2i) and nitriles (2j) were also successfully converted to the corresponding bis-benzofulvenes (3i and 3j) in 77 and 63% yields, respectively.…”

Diels-Alder Additions to 2,2’-Biaceanthrylene

“…[7][8][9][10] In previous work, we employed a palladium-catalyzed cyclopentannulation reaction [11][12][13][14][15][16] with trimethylsilyl-acetylene and 9-bromoanthracene to give aceanthrylene 1. 17 Subsequent ipso-bromination with N-bromosuccinimide gave 2 that could then be homo-coupled with a Nickel-catalyzed Yamamoto cross-coupling to give 2,2'-biaceanthrylene 3. The five-five ring-linked chromophores provided an opportunity to utilize the adjacent double bonds of the cyclopentene rings as a diene for Diels-Alder reaction chemistry.…”

Diels-Alder Additions to 2,2’-Biaceanthrylene

“…[7][8][9][10] In previous work, we employed a palladium-catalyzed cyclopentannulation reaction [11][12][13][14][15][16] with trimethylsilyl-acetylene and 9-bromoanthracene to give aceanthrylene 1. 17 Depending on the substrate utilized, the resulting major isolated material was either a 1:1 or a 1:2 adduct, while employing a 1:1 feed ratio of diene to dienophile. Similar differentiation was found in Diels-Alder reaction Scheme 1.…”