Aminobenzodione-based polymers with low bandgaps and solvatochromic behavior

Abstract

Pd-catalyzed amination polymerization of deep blue aminobenzodifuranone monomer 3-(4-bromo-phenyl)-7-(4-octylaminophenyl)-benzo[1,2-b:4,5-b′]- difuran-2,6-dione (M1) is described, as well as polymerization of symmetric dibromophenyl-benzodifuranone (M2), or the corresponding dibromophenylbenzodipyrrolidone (M3) with N,N′-dialkylated phenylenediamines (M4a,b). The resulting polymers P1-3 exhibit low bandgaps (1.08-1.47 eV), broad UV/vis absorption bands (400-900 nm), and a large solvatochromic shift up to 3140 cm-1 from n-hexane to hexamethylphosphoramide. Multiple linear regression analyses of max of the solvent-dependent solvatochromic UV/vis absorption bands of M1, P1 and P2a are presented, from which Kamlet-Taft and Catalán solvent parameters were determined. All monomers and polymers exhibit high extinction coefficients up to 8.6 × 104 L mol-1 cm-1 and high photostability, and might be suitable for electronic applications. © 2014 the Partner Organisations.