Development of Fluorescent 2-Pyrone Derivatives Using Ketene Dithioacetals for Organic EL Devices

Abstract

-In recent years, organic electro luminescent (EL) materials have received considerable attention due to their potential application in next-generation display devices with high brightness levels, wide color ranges, and wide viewing angles. Fluorescent 2-pyrone derivatives have been synthesized using a convenient method involving ketene dithioacetals, which emit fluorescence (red, green, and blue) in both solution (dichloromethane and ethanol) and solid state. The structure-activity relationships of various 2-pyrone derivatives have been clarified.

Synthesis of fluorescent aromatic species via ring transformation of α-pyranones and their application in OLEDs, chemosensors, and cell imaging

“…41,42 The Tominaga protocol, a facile method, was employed to prepare 2 H -pyran-2-one systems from ketene dithioacetals and ketones (Scheme 1). 43 Ketene dithioacetals 4 were conveniently synthesized from ethyl cyanoacetate, carbon disulphide and methyl iodide or dimethyl sulfoxide in the presence of a base. 44 Under basic conditions, 4 was further treated with aromatic ketones 5 containing α-Hs to afford 6-aryl-3-cyano-4-methylthio-2 H -pyran-2-ones 6 .…”

Synthesis, photophysical evaluation, and computational study of 2-methoxy- and 2-morpholino pyridine compounds as highly emissive fluorophores in solution and the solid state

“…We have found that the enol form greatly contributes to the fluorescence intensity in both nonpolar and polar solvents. In heterocyclic compounds, the arrangement of the electron-donating or electron-withdrawing groups affects the intramolecular charge transfer (ICT) and enhances the fluorescence intensity [18,[25][26][27]. In addition, we reported that the steric hindrance of the alkyl group reduces the molecular aggregation of 2-pyridone and induced AIEE-based fluorescence [18,19].…”

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

“…While most α-pyrones neither fluoresce in solution nor in the solid state specific substitution patterns have been identified for fluorophore design for this heterocyclic family. Tominaga and co-workers synthesized a series of α-pyrone derivatives with emission maxima between 400 and 675 nm in the solid state and between 486 and 542 nm in chloroform [16,24–26], including fluorescence quantum yields as high as 95% in solution and 58% in the solid state [16,24]. While these fluorophores were synthesized by cyclocondensation with ketene dithioacetals and substituted acetophenones other cyano-containing derivatives became accessible by desymmetrizing cyclocondensation of 1,2-diaroylacetylenes with ethyl cyanoacetate [27], similar to related studies with dialkyl malonates [28].…”