Microwave-assisted polycondensation of 4-octylaniline with dibromoarylene

Abstract

The Pd-catalyzed polycondensation of 4-octylaniline with various dibromoarylenes was carried out under microwave heating. Microwave heating led to a decrease in the reaction time and an increase in the molecular weight of the polymers as compared to conventional heating. Microwave heating also allowed the catalyst loading to be reduced to 1 mol %, yielding polymerization results that were comparable to those under conventional heating and 5 mol % catalyst. Investigations regarding field-effect transistors and organic photovoltaic cells using the obtained poly(arylamine) with azo-benzene units revealed that increasing the molecular weight of the polymer led to improved device performance, including hole mobility and power conversion efficiency. V C 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 536-542 EXPERIMENTAL Materials 4-Octylaniline, 4,4 0 -dibromobiphenyl, 4,4 0 -dibromostilbene, 2,7 0 -dibromo-9-fluorenone, 1,6 0 -dibromopyrene, tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ), tri-tert-butylphosphonium tetrafluoroborate (P(t-Bu) 3 ÁHBF 4 ), and NaOt-Bu were received from commercial suppliers and used without further purification. Anhydrous toluene was purchased from Kanto Chemical and used as a dry solvent. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS, CLEVIOS P VP AI 4083) was purchased from Heraeus. PC 70 BM (purity 99%) Additional Supporting Information may be found in the online version of this article.

Effect of Purification Solvent on Polymer Impurities and Device Performance

“…1 H NMR (400 MHz, CDCl 3 ): δ = 7.44 (d, J = 8.4 Hz, 4H), 7.13 (d, J = 8.4 Hz, 4H), 7.08 (br, 4H), 2.57 (t, J = 6.6 Hz, 2H), 1.60 (br, 2H), 1.28 (br, 10H), 0.88 (t, J = 6.8 Hz, 3H). The spectral data are essentially the same as the reported data …”

“…In contrast, the Buchwald–Hartwig aryl amination reaction has advantages in cost because it consists of coupling halogenated aryl compounds with arylamine derivatives, which are easily obtainable and inexpensive. Hartwig et al have reported synthesis of poly­(triarylamine)­s from aromatic dihalides and aromatic secondary diamines. , We have also reported synthesis of poly­(triarylamine)­s from aromatic dihalides and aromatic primary amines. − These reactions afford polymers with halogen and NH terminal units when the terminal units are not treated at the end of the polymerization. These terminal structures decrease the device performance. , For example, a halogenated terminal can be the hole carrier trap during device operation and inhibit the carrier flow .…”