Bis‐Cinnolines as n‐Type Semiconducting Material with High Electron Mobility and Thermal Stability and their Application in Organic Photovoltaic Cells

Abstract

Dedicated to Professor Eun Lee on the occasion of his retirement and 65th birthdayOrganic photovoltaic (OPV) devices [1][2][3][4] are attracting much attention as a new source of renewable energy. A major chemical interest in this area of research lies in the development of new organic semiconductors. Molecular design endows in an organic compound either a hole-transporting (p-type), electron-transporting (n-type), or ambipolar property through the incorporation of heteroatoms and new conjugation systems to the basic carbon framework. [5][6][7][8] The design of p-type semiconductors usually consists of installing electron-donating amino substituents on an aromatic system to raise the HOMO level. We recently discovered the p-type semiconductor properties of benzodifurans, and found it interesting that furans have received much less attention than thiophene and pyrrole semiconductors. This observation led us to explore a variety of aromatic rings bearing electron-deficient heteroatoms that may generally serve as n-type materials, which are less easy to design, and hence less-developed than the p-type materials. [5,6,[9][10][11][12][13][14][15] Herein, we report that a naphthalene-type molecule bearing two nitrogen atoms called cinnoline (Scheme 1) shows good n-type characteristics together with favorable thermal and morphological stabilities and high electron mobility (up to the order [a] Dr. Synthesis of 1,3-bis(3,4-Diphenylcinnolin-8-yl)benzene (p8-BCB)8-Bromo-3,4-diphenylcinnoline (240 mg, 0.665 mmol), 1,4-phenylenediboronic acid (54.4 mg, 0.328 mmol), PdA C H T U N G T R E N N U N G (PPh 3 ) 4 (75.8 mg, 0.0656 mmol), and Na 2 CO 3 (153 mg, 1.44 mmol) were added to degassed H 2 O (0.769 mL), EtOH (0.56 mL), and toluene (1.75 mL). The mixture was stirred at 120 8C for 18 h. After cooling to room temperature, the reaction was quenched with saturated aqueous NH 4 Cl. The mixture was filtered and washed several time with dichloromethane to give the title compound as a yellow solid (72.2 g). The filtrate was extracted with chloroform. The combined organic layers were dried over MgSO 4 and concentrated in vacuo. Recrystallization from toluene afforded the title compound as a yellow solid (78.0 mg), (total 150 mg, 0.235 mmol, 72 %). Mp: 338-339 8C. 1 H NMR (500 MHz, CDCl 3 ): d = 7.26-7.30 (m, 6 H, ArH), 7.33-7.35 (m, 4 H, ArH), 7.45-7.47 (m, 6 H, ArH), 7.53-7.55 (m, 4 H, ArH), 7.77-7.81 (m, 4 H, ArH), 7.96-7.98 (m, 4 H, ArH), 8.05 ppm (s, 4 H, ArH). 13 C NMR (125 MHz, CDCl 3 ): d = 125.0

Organocatalytic Electrosynthesis of Cinnolines through Cascade Radical Cyclization and Migration

“…The alkyne moiety of ortho-alkynyl acetophenone could be substituted with both electron-donating and electron-withdrawing substituents (4−19). Moreover, this strategy demonstrated good functional group tolerance, including H (4), alkyl groups (5−7, 16, 17), halogens (8−10), Ph (11), CO 2 Me (12), CF 3 (13,18), NHAc (14), and OMe (15,19). The good halogen tolerance supplied the potential application of further functionalization by the cross-coupling.…”

“…Pyridazine ring, a six-membered heterocycle with two nitrogen atoms at the adjacent positions, has constantly attracted the synthetic pursuit of both medicinal and synthetic chemists, due to its unique framework and attractive biological properties, − including antibacterial, antiulcer, antifungal, anticancer, and antihypertensive activities (Scheme ). Moreover, pyridazines have been widely used in electrochemistry , and photochemistry . Traditionally, a pyridazine ring can be constructed by the cyclization of hydrazine, , tetrazine, triazenes, or diazonium salt .…”

“…Moreover, pyridazines have been widely used in electrochemistry 12,13 and photochemistry. 14 Traditionally, a pyridazine ring can be constructed by the cyclization of hydrazine, 15,16 tetrazine, 17 triazenes, 18 or diazonium salt. 19 However, use of toxic reagents limits its application.…”

2,3-Dicyanopyrazines Substituted Styryl Electron-Donor Group and Its Application for OLED Emitting Materials

“…Introduced substituents were occasionally able to affect not only for the control of electronic levels but hole or electron transferring performances on the OLED device. Thus, it needs a careful consideration when the design of emitting materials [20]. Table 2 lists the efficiency of the fabricated device at a current density of 1.0 mA/cm 2 .…”

Tripyridyltruxenes: Thermally Stable Cathode Buffer Materials for Organic Thin‐Film Solar Cells

“…If the molecules are aligned on the electrode surface to induce a suitable dipole, the work function of the electrode is modified, and electron or hole flow across the interface is facilitated. We recently studied modulation of the work function [6] and de novo design of buffer materials, such as benzophosphole [7] and cinnolines, [8] as the basis of new p-conjugated organic frameworks. [9,10] These studies suggested the importance of the contact between the electrode and the buffer material, and of the molecular dipole that facilitates carrier extraction from the active layer to the electrode.…”