Synthesis And Properties Of Triazine And Quinoxaline Derivates For Organic Electron Transport Materials

Nowtodays, trizaine and quinoxaline derivatives were widely applied in the field oforganic light-emitting materials for their excellent photoelectric properties.In thispaper,some triazine and quinoxaline derivatives were prepared for electronic transportmaterials by Suzuki coupling reaction and other types of reaction, whose structure weredetermined by1HNMR, LC-MS and elemental analysis,photoelectronic properties wereinvestigated by UV-vis, CV and thermal stability were tested by DSC and TGA.It can besummarized as follows:Five star-shaped triazine derivatives,2,4,6-Triphenyl-[1,3,5]triazine(TRZH),2,4,6-Tris-(4-pyridin-3-yl-phenyl)-[1,3,5]triazine(TRZ4),2,4,6-Tri-pyridin-3-yl-[1,3,5]-triazine(TRZ6),2,4,6-Tris-([2,2’]Bipyridinyl)-[1,3,5]-triazine(TRZ7),2,4,6-Tris-(4’-pyridine-3-yl-biphenyl-4-yl)-[1,3,5]-triazine(TRZ8) were synthesized by controllabilitycondition and characterized by1HNMR, elemental analysis,LC-MS. The factors thatinfluenced the yield such as catalyst, solvent, base, concentration, reaction temperaturewere also studied and optimized further.Though comparing influence of their UV-visabsorption spectrum, electrochemical properties and thermal stability after introducingpyridyl and phenyl group,the results showed pyridyl group,an electron withdrawinggroup,brought these compounds obvious red-shift,lowered the LUMO and HOMOlevels and increased electron affinity(EA).In addition,the red-shift and increasing EAcould be also achieved by introducing phenyl group to adjust conjugation length.TheDSC and TGA indicated these series of triazine derivatives both had good thermalstability.By changing different substituent,-CH3, F, Phenyl, four quinoxaline derivatives, 4-Phenyl-2,6-di-quinoxalin-2-yl-pyridine(QNH),4-p-tolyl-2,6-Di-quinoxalin-2-yl-pyridine(QNM),4-(4-Fluoro-phenyl)-2,6-Di-quinoxalin-2-yl-pyridine(QNF),4-Biphenyl-4-yl-2,6-Di-quinoxalin-2-yl-pyridine(QNP) were synthesized and characterized by1HNMR,elemental analysis,LC-MS.The reaction condition had been optimized.After comparingdifferent substituent electronic effect,the result indicated their UV-vis absorptionspectrum displayed red-shift as conjugation effect(σ-π，p-π，π-π) enhanced, whichresulted in lowering LUMO levels especially when–H was substituted by phenylgroup.These quinoxaline derivatives thermal stability had been proved excellent too.