New cross π-conjugated aromatic polyketones: Synthesis and chemical properties

Two new cross pi-conjugated polyketones, (Ar-CO-Ar-C6H2(OC12H25)(2))(n) (Ar = p-phenylene (Polymer-1) and pyridine-2,5-diyl (Polymer-2)) have been synthesized via Suzuki-type organometallic polycondensation. Polymer-1 and Polymer-2 had number average molecular weights (Me) of 32,000 and 8000, respectively, in GPC analysis and were thermally stable up to 300 degrees C under N-2. Polymer-1 and Polymer-2 showed photoluminescence (PL) peaks at lambda(EM) = 466 and 515 nm in chloroform with quantum yields of Phi = 0.46 and 0.04, respectively. The PL peak position of Polymer-1 agrees with the electroluminescence (EL) peak observed with an ITO/PEDOT-PSS/Polymer-1/Ba:Al PLED configuration (lambda(EL) = 460 nm). PLs of Polymer-1 and Polymer-2 showed phosphorescence characteristics with long decay lifetimes of 0.58 and 1.08 s and quantum yields of 20% and 19% at 771< in frozen glass matrices, respectively. Cyclic voltammograms of Polymer-1 and Polymer-2 films on a Pt plate showed electrochemical reduction (n-doping) peaks at -2.17 and -1.91 V vs. Ag+/Ag, respectively. (C) 2013 Published by Elsevier B.V.