Study On Synthesis And Optical Properties Of Conjugated Compounds Containing Nitrogen Heterocycle

With the development of information, people demand better displ-ay. Organic light-emitting diodes has gradually cause the attention of people because of their low cost, low voltage driver, short response t-ime, small volume, wide angle, high resolution, good flexibility, etc. Owing to the information technique obtained the progress by leaps an-d bounds development and the good property, OLED becomes one of the most popular research direction in this field at present.Carbazole, benzimidazole and indole are typical electron-rich mole cules. They have good ability of electron-transport and hole-transport, furthermore, they have good solubitily and thermal stability. Their der-ivatives were widely used in organic electroluminescent devices.In this paper, a series of conjugated compouds containing carbaz-ole, benzimidazole, indole ring were synthesised. The reaction conditi-ons of some compouds were optimized and the optical property of so me compouds were studied.1. Synthesis of carbazole and benzimidazole derivatives.(1)9-(6-(9H-carbazol-9-yl)pyridin-2-yl)-3-iodo-9H-carbazole (la),2,6-bis(3-iodo-carbazolyl)pyridine (2a),3,6-diiodo-9-(6-(3-iodo-9H-carba-zol-9-yl) pyridin-2-yl)-9H-carbazole (3a) and2,6-bis(3,6-diiodo-9H-ca rba-zol-9-yl)pyridine(4a) were synthesised respectively through iodo-r-eaction with2,6-di(9H-carbazol-9-yl)pyridine as raw material. The iodo conditions were optimized, and the better process line were determin-ed.(2)9-(6-(9H-carbazol-9-yl)pyridin-2-yl)-3-(benzimidazolyl)-9H-carb-azole (1b),2,6-bis(3-(1H-benzo[d]imidazol-1-yl)-9H-carbazol-9-yl)pyridin e (2b),9-(6-(3-(benzimid-azolyl)-carbazolyl)pyridin-2-yl)-3,6-di(benzimid azolyl)carbazole (3b) and2,6-bis(3,6-di(1H-benzimidazolyl)-carb-azolyl) pyridine(4b) were synthesised respectively through Ullmann reaction w-ith1a,2a,3a,4a and benzimidazole as raw material. All the target compound were confirmed by IR,1H NMR.2. Synthesis of conjugated compound containing indole ring(1) Indole-3-carbaldehyde (6a),2,6-diindolyl pyridine (7a),2,6-bi-s(1H-indole-3-carbaldehyde)pyridine (7b),1,4-diindolylbenzene (8a),1,4-bis(1H-indole-3-carbaldehyde)benzene (8b) and1-(4’-bromobiphenyl-4-yl)-1H-indole-3-carbaldehyde (9a) were synthesized through Vilsyemer reaction and Ullmann reaction. The synthesis condition of compound7b was optimized.(2)2,6-bis(3-styryl-lH-indol-l-yl)pyridine (7c),2,6-bis(3-((E)-2-(na-phthalen-yl)vinyl)-1H-indol-1-yl)pyridine (7d),1,4-bis(3-styryl-1H-indolyl) benzene (8c),1,4-bis(3-((E)-2-(naphthalene-l-yl)vinyl)-1H-indol-1-yl) be-nzene (8d),1,4-bis(3-(4-methy-lstyryl)-1H-indol-1-yl)benzene (8e),1-(4’-bromobiphenyl-4-yl)-3-styryl-1H-indole (9b),1-(4’-bromobiphenyl-4-yl)-3-(2-(naphthalen-1-yl)vinyl)-1H-indole (9c) and1-(4’-bromo-biphenyl-4-yl)-3-(4-methylstyryl)-1H-indole (9d) were synthesized respectively th rough Wittig reaction with7b,8b,9a as raw material. All the targetc ompound were confirmed by IR,1H NMR and13C NMR.3. Study on the optical property of compound8a-8eThe UV-Vis absorption spectra and luminescent spectra of comp-ound8a-8e were determined. The result shows that a significant red-shift in both absorption and emission spectra of8a-8e was happened with the solvent polarity and the degree of conjugation increasing.