Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

Abstract

Three compounds, bearing a quinazoline unit as the acceptor core and carbazole, dimethyldihydroacridine, or phenothiazine donor moieties, were designed and synthesized in two steps including a facile copper-catalyzed cyclization and a nucleophilic aromatic substitution reaction. The photophysical properties of the compounds, based on theoretical calculations and experimental measurements, as well as the electrochemical and thermal properties, are discussed. The synthesized compounds form glasses with glass-transition temperatures ranging from 116 °C to 123 °C. The ionization potentials estimated by cyclic voltammetry of the derivatives were in the range of 5.22–5.87 eV. The 3,6-di-tert-butylcarbazole-substituted quinazoline-based compound forms a sky-blue emitting exciplex in solid mixture with the acceptor 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine as well as an orange emitting exciplex with the donor 4,4′,4″-tris[3-methylphenyl(phenyl)amino]triphenylamine. A white OLED based on these versatile exciplex systems with a relatively high maximum brightness of 3030 cd/m2 and an external quantum efficiency of 0.5% was fabricated.

Efficient Synthesis of Conjugated 1,3,4-Thiadiazole Derivatives under Suzuki Cross-Coupling Reactions

“…Quinazoline is a chemical compound containing fused pyrimidine and benzene heterocyclic rings, with broad application in life and science. Some of them are reported as potential compounds in medicine [2], agrochemistry, and due to their fluorescent effects, they are largely used in material science as OLEDs [3]. Various procedures on quinazoline ring formation can be found in the literature.…”

Synthesis and Structure‐Photophysics Evaluation of 2‐N‐Amino‐quinazolines: Small Molecule Fluorophores for Solution and Solid State

“…Besides such a broad and diversified spectrum of biological activities, quinazolines have also attracted emergent interest in materials research. The electron deficient nature of the heteroaromatic core turns it to an unique molecular scaffold for the design of donor‐π‐spacer‐acceptor chromophores, [19] low‐band gap materials for organic electronics and organic light emitting diodes (OLEDs), [20] exciplex‐forming and/or dual emissive compounds, [21,22] and chemical sensors [23] . For instance, the donor‐π‐spacer‐acceptor chromophore I has been used in dye sensitized solar cells (DSCCs), [24] and the quinazoline ligated iridium complex II was used as a yellow‐red light emitting phosphorescent dopant in polymer matrixed OLEDs [25] .…”