Dinaphthotetrathiafulvalene Bisimides: A New Member of the Family of π‐Extended TTF Stable p‐Type Semiconductors

Abstract

Air-stable organic semiconductors based on tetrathiafuluvalene (TTF) were developed by synthesising a series of dinaphthotetrathiafulvalene bisimides (DNTTF-Im) using electron-donating TTF, π-extended naphthalene, and electron-withdrawing imide. Electron-spin-resonance spectroscopy and X-ray single-crystal structure analysis of aryl-substituted DNTTF-Im radical cations confirmed that localisation of the spin resides on the electron-donating TTF moiety. The organic field-effect transistor properties derived from the use of highly crystalline n-butyl (C4) and n-hexyl(C6)-substituted DNTTF-Im were assessed. The hole carrier mobility of C6-DNTTF-Im was improved from 3.7×10 cm V s to 0.30 cm V s in ambient conditions. This is attributed to the raise of the substrate temperature from 25 °C to 200 °C during sublimation. The XRD and microscopy analysis suggested that increasing the substrate temperature accelerates the end-on packing resulting in larger grains suitable for hole charge transport parallel to the substrate.

Semiconducting π‐Extended Tetrathiafulvalene Derivatives

“…By combining electron‐donating TTF and an electron‐withdrawing imide with a larger π‐conjugated framework, Yamashita et al. attempted to improve both the charge‐transport characteristics and chemical stability of the developed semiconductors . The HOMO and LUMO levels of DN‐TTF, C1‐DN‐TTF‐Im, and C1‐DB‐TTF‐Im were calculated by using the Gaussian 09 program at the B3LYP/6‐31G(d) level.…”

“…By combining electron-donating TTF and an electron-withdrawing imide with al arger p-conjugated framework, Yamashita et al attempted to improve both the charge-transport characteristics and chemical stabilityo ft he developed semiconductors. [54] The HOMO and LUMO levelso fD N-TTF,C 1-DN-TTF-Im, and C1-DB-TTF-Im were calculated by using the Gaussian 09 program at the B3LYP/6-31G(d) level. The HOMOs of these compounds are localised on the electron-donatingT TF moiety, whereas the LUMOs are localised on the naphthalene moiety in the case of DNTTF and the electron-withdrawing naphthoand benzoimide moieties in the case of C1-DNTTF-Im and C1-DBTTF-Im, respectively.O wing to the similarity of the HOMO levels of C1-DNTTF-Im and C1-DBTTF-Im, it was expected that DNTTF-Im would be stable in air in am anner similart ot hat of DBTTF-Im.…”

“…Scheme7.Syntheses of C4-and C6-DNTTF-Im derivatives. [54] NBS = N-bromosuccinimide, AIBN = azobisisobutyronitrile. face-on packing structures.…”

“… Syntheses of C4‐ and C6‐DNTTF‐Im derivatives . NBS= N ‐bromosuccinimide, AIBN=azobisisobutyronitrile.…”

New near-infrared absorbing conjugated electron donor–acceptor molecules with a fused tetrathiafulvalene–naphthalene diimide framework

“…13,14 With the passage of time, abundant properties of TTF have been exploited, which made them intensively studied in many fields including chemical sensors, molecular devices as well as optoelectronic devices in the recent years. 15–29 Among these TTF derivatives, TTF based conjugated electron donor–acceptor systems have received extensive attention. This is because the incorporation of TTF units in a conjugated way can raise the highest occupied molecular orbital (HOMO) energy levels of the D–A molecules, redshift the absorption and enhance the intermolecular interaction.…”