Design,Synthesis And Properties Of Aza Fused-Rings Compoundts

Fused polycyclic aromatic hydrocarbons were composed of two or more benzene rings connected to each other.They have become a primary focus in the field of organic light-emitting diodes(OLEDs),organic field-effect transistors(OFET),fluorescent sensors and so on due to their unique ?-conjugated structure,easy modification and excellent photoelectric properties.As a kind of fused polycyclic aromatic hydrocarbons,helicenes show good potential applications in the fields of organic electroluminescent materials and nonlinear optical materials because of their unique screw-shaped aromatic skeletons and non-planar ?-electron systems.The small fused-ring molecules linked by vinyl bonds form Donor-?-Acceptor(D-?-A)type molecular structure.The extended ?-conjugated system can facilitate the carrier transport and improve fluorescence efficiency of the material,so they are also widely used in luminescent materials.In this dissertation,we mainly designed and synthesized a diaza fused-ring compound and two vinyl bond bridged D-?-A molecules:10-(hexyloxy)dibenzo[a,j][3,7]phenanthroline,(Z)-8-(hexyloxy)-2-(2-(naphthalene-2-yl)vinyl)quinoline and(E)-4-(2-(9,9-dihexyl-9H-fluoren-2-yl)vinyl)pyridine,and all compounds were verified.The optical properties,electrochemical properties and thermal properties were also investigated.8-Hydroxy-2-methylquinoline and 3-bromoquinoline as starting reactants were used to synthesize the diaza fused-ring compound through photocyclization and verified by 1H NMR,13C NMR and HRMS.The twisted configuration of helicene can not only shorten the ?-system but also be beneficial for relieving close-packing interactions.10-(hexyloxy)dibenzo[a,j][3,7]phenanthroline exhibited decomposition temperature of 176.4 0C and excellent solubility.The maximum absorption peaks and emission peaks in hexane,dichloromethane,tetrahydrofuran,acetonitrile and methanol solutions ranged from 296 to 300 nm and 452 to 493 nm,respectively.The PL peak in film-state underwent bathochromic shifts at 499 nm.The fluorescence quantum yield was up to 28.09%in methanol.The HOMO,LUMO energy levels and the band gap of the compound were estimated to be-4.84,-1.40,and 3.44 eV,respectively.(2)-8-(hexyloxy)-2-(2-(naphthalene-2-yl)vinyl)quinoline which the 8-(hexyloxy)quinoline and the naphthalene molecule linked by a vinyl bond was obtained through the Wittig reaction.1H NMR,13C NMR,HRMS and X-ray were used to verify the compound.The compound crystallizes in monoclinic P21/n space group with four independent molecule in an asymmetric unit.The dihedral angle of quinoline and the naphthalene rings is 9.3°.To the best of our knowledge,it is the first example of quinoline-based stilbene-like molecules with the "cis" configuration reported so far.The maximum absorption peaks and emission peaks in tetrahydrofuran,ethyl acetate,trichloromethane,acetonitrile,and methanol solutions were measured from 281 to 283 nm and 435 to 467 nm,respectively.The fluorescence quantum yield in methanol solution is the highest,up to 22.35%.The HOMO,LUMO energy levels and the band gap of the compound were estimated to be-4.97,-2.22 and 2.75 eV,respectively.The decomposition temperature of the compound was 222.13 ?.(E)-4-(2-(9,9-dihexyl-9H-fluoren-2-yl)vinyl)pyridine with the 9,9-(dihexyl)fluorene and pyridine molecules linked by a vinyl bond was synthesized through Heck reaction.The thermal measurement showed that the decomposition temperature Td was 225.23 ?.The maximum absorption peaks in hexane,toluene,dichloromethane,ethyl acetate,and acetonitrile solutions ranged from 326 to 330 nm,and the maximum emission peaks ranged from 390 to 411 nm.The fluorescence quantum yield was up to 13.35%in dichloromethane.In the electrochemical measurement,the compound underwent an irreversible redox process with HOMO and LUMO energy levels of-4.77 and-1.91 eV,and the band gap of 2.76 eV,respectively.