The efficient blue photoluminescence of pyrazolo-[3,4-b]-quinoline derivatives and the energy transfer in polymer matrices

Exploring Reversible Quenching of Fluorescence from a Pyrazolo[3,4‐b]quinoline Derivative by Protonation

“…[37,38] Under UV radiation, bright blue light emission can be observed from a solution of PAQ5 in ethanol (Figure 1 were measured with a 310 nm cut-off filter, and the weak peak at 600 nm is an instrumental artefact due to partial leakage of excitation light at 300 nm.…”

“…Pyrazolo [3,4-b]quinoline derivatives (PAQs) are a promising class of organic emitters used in organic light emitting diodes (OLEDs) due to their bright blue or greenish-blue light emission, [32][33][34][35][36] excellent quantum efficiencies [37,38] and electrontransport properties. [39][40][41] Our recent work revealed a potential use of 1-phenyl-3,4-dimethyl-1H-pyrazolo [3,4-b]quinoline (PAQ5) as an emitter dopant to stabilize the colour characteristics.…”

“…However, a recent report on an unsubstituted 1H-pyrazolo [3,4-b]quinoline showed complicated quenching behaviour: it exhibits fluorescence from the molecule and from an H-bonded complex, but its dimer is non-fluorescent. [42] Although the photophysical properties of substituted PAQs appear to be very different from those of unsubstituted ones, [37] any kind of fluorescence quenching can be devastating by limiting the efficiency and luminance of light emission as far as organic electroluminescent devices are concerned.…”

Growth, spectral, optical, thermal, and mechanical behaviour of an organic single crystal: Quinolinium 2-carboxy 6-nitrophthalate monohydrate

“…They are widely used in electrochemical sensing [5] and optical switching devices [6]. Quinoline derivatives, give much attention due to their potential applications in the field of Organic Light Emitting Diodes (OLEDs) [7][8][9] and polymer-LED materials [10,11]. Quinoline derivatives are also used in energy conversion devices [12,13].…”

Molecular Iodine: A Versatile Catalyst for the Synthesis of 4-Aryl-3-methyl-1-phenyl-1H-benzo[h]pyrazolo[3,4-b]quinoline-5,10-diones in Water

“…4 In the past several decades, three general strategies for the synthesis of pyrazolo [3,4-b]quinolines have been developed: 1) by the Friedlander condensation reaction of 2-aminobenzophenones and pyrazolin-5-ones. 5 Availability of 2-aminobenzophenones limits the range of applicability of this reaction; 2) by cyclization of 4-arylidenepyrazolin-5-ones with anilines 6 or 5-N-arylpyrazoles with aromatic aldehydes.…”