Luminescent materials incorporating pyrazine or quinoxaline moieties

Abstract

International audienceThough the past few decades, the development of new luminescent materials has received a lot of attention due to their applications as fluorescent sensors, in biological microscopy and in optoelectronic devices. Most of these applications are relied on intramolecular charge transfer (ICT). Presence of electron withdrawing N-heterocycles such as pyrazine and quinoxaline rings appeared therefore particularly interesting to be used as electron-attracting part in π-conjugated structures. Moreover, presence of nitrogen atoms with lone electron pairs allows to the pyrazine and the quinoxaline ring to act as effective and stable complexing agent or as base that can be protonated. This review reports luminescent small molecules and oligomers including a pyrazine or quinoxaline ring in their scaffold highlighting their applications related to photoluminescence and electroluminescence

New V-shaped push-pull systems based upon 4,5-di(hetero)aryl substituted pyrimidines: their synthesis and application for the detection of nitroaromatic explosives

“…[39][40][41] Also some pyrimidines exhibit second order nonlinear optical properties. 42,43 In continuation of our previous studies on (hetero)aryl substituted bithiophenes and their analogues, as photosensitizers for dye-sensitized solar cells, 22,23,44 and taking into account the results reported by other groups on the use of pyrimidine-triphenylamine and pyrimidine-carbazole dyads in optical materials, 35,36 we have focused our attention on donor-π-acceptor organic dyes bearing the pyrimidine fragment, as chemosensors for nitroaromatic explosives. In this communication we report the synthesis of pyrimidine-based V-shaped new organic fluorophores with yellow-green emission, their photophysical properties and sensitivity towards nitroaromatics.…”

“…[32][33][34] Pyrimidine is a very π-deficient heterocycle, and as a core it can be used as an electronwithdrawing component in push-pull structures. 35,36 During the past decade, hundreds of pyrimidine-bearing chromophores have been designed. In particular, numerous aryl substituted pyrimidines have been studied as fluorescent dyes.…”

“…In particular, numerous aryl substituted pyrimidines have been studied as fluorescent dyes. [35][36][37][38] Moreover, it should be noted that arylvinyl pyrimidines are now considered as well established structures of two-photon absorption dyes. [39][40][41] Also some pyrimidines exhibit second order nonlinear optical properties.…”

New "turn-off" fluorescence sensors to detect vapors of nitro-explosives on the basis of 4,6-bis[5-(heteroaryl)thiophen-2-yl] substituted 5-(4-tert-butylphenyl)pyrimidines

“…Indeed, we have been motivated to synthesize D-π-A-π-D conjugates 7a-c, in which electrondonating groups are attached to 4-and 6-positions of the pyrimidine ring via the thiophene spacer and 4-tertbutylphenyl substituent is incorporated at C-5 of pyrimidines. Although some 4,6-(hetero)aryl substituted pyrimidines have been synthesized, 28,41 no reports on 4,6-bis(carbazol-3-yl) pyrimidines have so far been published.…”

A facile, metal-free, oxidative coupling of new 6-(hetero)aryl-[1,2,5]-oxadiazolo[3,4-b]pyrazines with pyrroles, indoles and carbazoles

“…4 Indeed, [1,2,5]-oxadiazolo [3,4-b]-pyrazines have attracted considerable attention of chemists, as heat-resistant explosive materials (for example, see Figure 1). 5 Page 280 © ARKAT-USA, Inc. [1, 2,5]Oxadiazolo [3,4-b]pyrazines proved to exhibit a variety of physiological properties, such as anticancer, 6 anti-HIV, 7 and antibacterial activities. 8 For this reason the syntheses of 6-(hetero)aryl- [1,2,5]oxadiazolo [3,4-b]pyrazine -pyrrole (indole or carbazole) hybrid molecules appear to be rather interesting for elucidation of their biological, photophysical and electrochemical properties.…”