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

Two new cross π-conjugated polyketones, (Ar CO Ar C 6 H 2 (OC 12 H 25 ) 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 ( M n ) of 32,000 and 8000, respectively, in GPC analysis and were thermally stable up to 300 °C under N 2 . Polymer-1 and Polymer-2 showed photoluminescence (PL) peaks at λ EM = 466 and 515 nm in chloroform with quantum yields of Φ = 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 ( λ 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 77 K 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.