1 Ocak 2004 Dergi makalesi Açık Erişim

Zhao, L; Perepichka, IF; Turksoy, F; Batsanov, AS; Beeby, A; Findlay, KS; Bryce, MR

JSON-LD (schema.org)

{
  "@context": "https://schema.org/", 
  "@id": 94797, 
  "@type": "ScholarlyArticle", 
  "creator": [
    {
      "@type": "Person", 
      "name": "Zhao, L"
    }, 
    {
      "@type": "Person", 
      "name": "Perepichka, IF"
    }, 
    {
      "@type": "Person", 
      "name": "Turksoy, F"
    }, 
    {
      "@type": "Person", 
      "name": "Batsanov, AS"
    }, 
    {
      "@type": "Person", 
      "name": "Beeby, A"
    }, 
    {
      "@type": "Person", 
      "name": "Findlay, KS"
    }, 
    {
      "@type": "Person", 
      "name": "Bryce, MR"
    }
  ], 
  "datePublished": "2004-01-01", 
  "description": "A series of 2,5-di(aryleneethynyl) pyrazine derivatives has been synthesised in 23-41% yields by two-fold reaction of 2,5-dibromo-3,6-dimethylpyrazine 3 with ethynylarenes (arene=phenyl, 2-pyridyl, 4-ethylphenyl, 4-chlorophenyl, 4-biphenyl) under standard Sonogashira conditions [CuI, Pd(PPh3)(2)C(l)2, NEt3, THF]. Compound 3 has been converted into 2,5-diethynyl-3,6-dimethylpyrazine, which reacts with 2-iodothiophene to yield 2,5-bis(thien-2-ylethynyl)-3,6-dimethylpyrazine. In the X-ray crystal structure of 2,5-di(phenylethynyl)-3,6-dimethylpyrazine 4 the two phenyl rings are parallel and the pyrazine ring is inclined to their planes by 14.2degrees. Quantum chemical calculations establish that the HOMO-LUMO gap for 4 (3.56 eV) is lower than that of di(phenylethynyl) benzene 12 (3.72 eV). The nitrogen atoms of 4 serve to localise the HOMO on the central ring's carbon atoms, resulting in a quinoidal-type population, in contrast to 12. Cyclic voltammetric studies establish that 4 undergoes a reduction to the radical anion at ca. -1.9 V (vs. Ag/Ag+ in MeCN), which is almost reversible at high scan rates (500 mV s(-1)). The UV-vis absorption and photoluminescence profiles of 4 in cyclohexane are similar to those of 12; the emission for 4 (lambda(max) 379 and 395 nm) is red-shifted compared to 12. Single-layer OLEDs using MEH-PPV as the emissive polymer show significantly enhanced external quantum efficiencies (up to 0.07%) when 20% by weight of 2,5-di(biphenyl-4-ethynyl)-3,6-dimethylpyrazine 8 is added as a dopant: this is ascribed to the enhanced electron-transporting properties of the pyrazine system.", 
  "headline": "2,5-di(aryleneethynyl)pyrazine derivatives: synthesis, structural and optoelectronic properties, and light-emitting device", 
  "identifier": 94797, 
  "image": "https://aperta.ulakbim.gov.tr/static/img/logo/aperta_logo_with_icon.svg", 
  "license": "http://www.opendefinition.org/licenses/cc-by", 
  "name": "2,5-di(aryleneethynyl)pyrazine derivatives: synthesis, structural and optoelectronic properties, and light-emitting device", 
  "url": "https://aperta.ulakbim.gov.tr/record/94797"
}