Isomeric Dibenzoheptazethrenes for Air‐Stable Organic Field‐Effect Transistors

Abstract

Singlet diradicaloids hold great potential as semiconductors for organic field‐effect transistors (OFETs). However, their relative low material and device stabilities impede the practical applications. Here, to achieve balanced stability and performance, two isomeric dibenzoheptazethrene derivatives with singlet diradical character were synthesized in a concise manner. Benefitting from the aromatic stabilization, both compounds display a small diradical character and large singlet–triplet gap, as corroborated by variable‐temperature electron paramagnetic resonance spectra, single‐crystal analysis, and theoretical calculations. OFET devices based on single crystals showed a high hole mobility of 0.15 cm2 V−1 s−1, which is the highest for zethrene‐based semiconductors. Both isomers exhibited remarkable material stability in air‐saturated solutions as well as excellent bias‐stress and storage stability in device under ambient air.

High-mobility semiconducting polymers with different spin ground states

“…Open-shell organic molecules with high mobility will enable long spin transport distance which is crucial for spin-related applications 12 – 14 . However, there are few reports of small open-shell molecules with high charge carrier mobilities 10 , 15 – 17 . This is because the use of steric hindrance groups prevents close packing of molecules, and increasing the conjugation length requires more complex synthetic steps.…”

Polycyclic aromatic hydrocarbon-based organic semiconductors: ring-closing synthesis and optoelectronic properties

“…71–73 Accordingly, 45–47 were achieved via combined strategies but the diketone product after Friedel–Crafts alkylation reaction required two steps, nucleophilic addition and reduction reactions with SnCl 2 , to arrive at the target molecules. 74–76 It is worth noting that the strategy of combining addition and reduction reactions is appropriate for five-membered rings formed by the Friedel–Crafts alkylation reaction (Fig. 8), where 48 is an example of this.…”

Air Stable Chalcogen-Doped Rubicenes with Diradical Character

“…By monitoring their maximum absorption peaks (Fig. S6), the τ 1/2 were determined to be 62, 52, and 66 days (fitted from first-order kinetics 35 ) for O-, S-, and Se-rubicenes, respectively. This excellent air stability may be ascribed to the twist structures of rubicenes, 36 which is rare and astonishing considering the diradical distances are very small in these rubicenes.…”

“…The y 0 values of O-, S-, and Serubicene are 0.20, 0.21, and 0.17, respectively, suggesting modest diradical characters. [34][35]46 The modest…”