1,5-, 2,6- and 9,10-distyrylanthracenes as luminescent organic semiconductors

Afshin Dadvand,Andrey G Moiseev,Federico Rosei,Hong Meng,Dmitrii F Perepichka,Francine Bélanger-Gariépy,Wei-Hsin Sun

doi:10.1039/c3tc30247d

Abstract

We report the synthesis, molecular and crystal structures, optoelectronic properties and organic field-effect transistor (OFET) studies of three isomeric distyrylanthracene derivatives 2,6-DPSAnt, 1,5-DPSAnt and 9,10-DPSAnt. The analysis of the structure–property relationships reveals that π-conjugation in this series is defined by two competing factors: the co-planarity of the styryl substituents (highest in 2,6-DPSAnt) and the electronic communication through the anthracene core (strongest in 9,10-DPSAnt). The charge-transport properties of the compounds, on the other hand, are primarily controlled by the solid state packing which is more efficient for the linear 2,6-DPSAnt derivative. Accordingly, the highest field-effect mobility (up to 0.75 cm2 V−1 s−1) was measured for 2,6-DPSAnt. Unexpectedly high charge mobility of 1,5-DPSAnt (up to 0.15 cm2 V−1 s−1) was attributed to excellent thin-film morphology (nearly layer-by-layer growth) and favorable molecular packing in the films, different from that found in single crystals. Unfavorable molecular packing and poor film morphology observed for 9,10-DPSAnt predictably led to no transistor properties being observed for this isomer. Both 2,6-DPSAnt and 1,5-DPSAnt afforded light-emitting transistors with green light emission area localized near an electron-injecting electrode.

Highlights

The semiconducting conjugated organic molecules have received signi cant recent interest as they are the basis for a fundamental understanding of charge transport in the solid state and enable innovative technologies such as organic light-emitting diodes (OLEDs),[1,2,3] organic eld-effect transistors (OFETs)[4,5] and organic photovoltaics (OPVs).[6,7] The tunability of properties, multifunctionality and low-temperature processing are the three major advantages of molecular semiconductors (MSCs), pushing forward their use in optoelectronics
Disubstituted anthracenes 2,6-DPSAnt, 1,5-DPSAnt and 9,10DPSAnt were synthesized by Suzuki coupling of corresponding dibromoanthracenes with 4-pentylphenylvinylene boronic ester (Scheme 1)
Thermogravimetric analysis (TGA) measurements under nitrogen showed no decomposition until evaporation of the compounds at 410 C (2,6-DPSAnt), 360 C (1,5-DPSAnt) and 350 C (9,10-DPSAnt)

Summary

Introduction

The semiconducting conjugated organic molecules have received signi cant recent interest as they are the basis for a fundamental understanding of charge transport in the solid state and enable innovative technologies such as organic light-emitting diodes (OLEDs),[1,2,3] organic eld-effect transistors (OFETs)[4,5] and organic photovoltaics (OPVs).[6,7] The tunability of properties, multifunctionality and low-temperature processing are the three major advantages of molecular semiconductors (MSCs), pushing forward their use in optoelectronics. In 2,6-DPSAnt, the solid state packing causes a slight distortion of the anthracene ring: the largest outof-plane shi observed for C-2 and C-6 is 0.04 A.

Results

Conclusion