A Novel Thiophene-Fused Polycyclic Aromatic with a Tetracene Core: Synthesis, Characterization, Optical and Electrochemical Properties

Abstract

FeCl3-mediated oxidative cyclization was successfully used to construct an extended thiophene-pendant pyrene skeleton and synthesize a novel thiophene-fused polycyclic aromatic (THTP-C) with a tetracene core. The identity of the compound was confirmed by 1H-NMR, 13C-NMR, MS, and elemental analysis. Meanwhile, a single crystal of THTP-C was obtained and analyzed by X-ray single-crystal diffraction. THTP-C has a “saddle” shaped π-conjugated 1-D supramolecular structure, and favors highly ordered self-assembly by π-π interactions as evidenced by its concentration-dependent 1H-NMR spectra in solution. The optical properties of THTP-C were investigated by ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy and its electrochemical properties were investigated by cyclic voltammetry (CV). The relatively large band gap (2.86 eV), low EHOMO level (−5.64 eV) and intermolecular π-π interactions imply that THTP-C has a high stability against photo-degradation and oxidation, and may be a promising candidate for stable hole-transporting materials.

Hole transport and current–voltage characteristics of PEO/PVP/cobalt nitrate polymer blend electrolytes

“…The HOMO and LUMO energy levels of these films are comparable to the work functions of some of the widely used metals in device fabrication. [ 80 ]…”

“…The HOMO and LUMO energy levels of these films are comparable to the work functions of some of the widely used metals in device fabrication. [80] Also, the samples are operated in a wide potential window indicating the electrochemical stability, which is necessary for optoelectronic applications. [81] The values of electrochemical bandgaps and the optical bandgaps are approximately equal and a decreasing trend was observed in both.…”

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

“… The latter ring-closure turned out to be crucial for utilization in solution-processed OFET devices, and 123.3 showed an exceptional hole mobility for a perylene-based system. Related work from Duan, Nishioka, et al. , and from the Müllen group described the preparation of the tetrathiophene system 123.5a – c . These molecules were similarly obtained, by using either photochemical or chemical oxidation in the ring-forming step ( 123.5a could not be obtained via chemical oxidation).…”

“… a Reagents and conditions: (a) 2-(tributylstannyl)­thiophene, Pd­(PPh 3 ) 4 , toluene, overnight, reflux; (b) I 2 , h ν at 300 nm, toluene, overnight; (c) Pd­(PPh 3 ) 4 , DMF, 100 °C; (d) Pd­(PPh 3 ) 4 , toluene, Ar atm, 110 °C, 7–16 h; (e) I 2 , h ν at 300 nm, toluene, Ar atm, overnight, rt; (f) , FeCl 3 , CH 3 NO 2 , DCM, 0 °C, 15 min; (g) FeCl 3 , CH 3 NO 2 , DCM, Ar atm, rt, 30 min. …”