Synthesis and Characterization of 1,2,4-Oxadiazole-Based Deep-Blue and Blue Color Emitting Polymers

Abstract

Two donor-acceptor-donor monomers such as 3,5-bis(4-bromophenyl)-1,2,4-oxadiazole (BOB) and 3,5-bis(5-bromothiophen-2-yl)-1,2,4-oxadiazole (TOT) incorporating electron transporting and hole blocking 1,2,4-oxadiazloe moiety were copolymerized with light emitting fluorene derivative via Suzuki polycondensation to afford two new polymers, PFBOB and PFTOT, respectively. The optical studies for polymers PFBOB and PFTOT revealed that the band gaps are 3.10 eV and 2.72 eV, respectively, and polymer PFBOB exhibited a deep-blue emission while polymer PFTOT showed blue emission in chloroform and as thin film. The photoluminescence quantum efficiencies ( f ) of polymers PFBOB and PFTOT in chloroform calculated against highly blue emitting 9,10-diphenylanthracene (DPA,  f = 0.90) were 1.00 and 0.44, respectively.

Direct heteroarylation polymerization of a π-conjugated polymer with degradable 1,2,4-oxadiazole linkers

“…T-ODA-T was synthesized according to the literature. 10 Treating thiophene-2-carbonitrile with hydroxylamine forms thiophene-2-amidoxime. The amidoxime can then be coupled with thiophene-2-carbonyl chloride to yield T-ODA-T .…”

“…[7][8][9] However, 1,2,4-oxadiazoles have only been explored to a limited extent as conjugated polymer building blocks, with no mention of their degradability. [10][11][12] Here we present two semiconducting polymers with π-conjugated backbones consisting of thiophene and degradable 1,2,4-oxadiazole moieties. These polymers exhibit photoluminescent quantum yields (PLQYs) as high as 40% and are candidates as degradable luminescent materials.…”

“…7–9 However, 1,2,4-oxadiazoles have only been explored to a limited extent as conjugated polymer building blocks, with no mention of their degradability. 10–12…”

Excited-State Dynamics of Room-Temperature Phosphorescent Organic Materials Based on Monobenzil and Bisbenzil Frameworks

“…bands. These bands were typical of the benzil moiety [ 30 , 32 ], but not tolane [ 33 , 34 , 35 , 36 , 37 ]. An emission from higher excited states implied anti-Kasha behavior, and many molecules were known to exhibit the emission [ 13 , 38 , 39 ].…”