Synthesis And Property Of Molecules Based On Perylene Diimides And Naphthalene Diimides

Owing to their excellent opto-electronic property,good chemical stability and thermal stability,perylene bisimide and naphthalene diimide derivatives have been widely used in organic solar cells,organic field-effect transistors,self-assembly and fluorescent probes and so on.While there were few reports concerning the PDI-based luminogens for OLEDs,regardless of their excellent properties.Thus,the developing of more perylene bisimide derivatives for OLED devices with better performance is desired for the application of OLEDs in flat panel display and solid state lighting.Like traditional organic lighting materials,PDIs and NDIs tend to aggregation in high concentrations or solid states caused by their intermolecular strong ?-? stacking or dipole-dipole interactions,leading to fluorescence quenching,which limited their possible application in solid lighting or bio-imaging.Thus,it is of great importance to alleviate the unwanted intermolecular ?-? stacking and improve the emission efficiency in the solid state for their development in organic electronics application.As a kind of big ?-conjugation planar structure with electron-withdrawing property,naphthalene diimides derivatives have advantages of easy synthesization and modification,spectrum adjustment,Through reasonable molecular modification,the fluorescent spectra of NDIs could fall in red even deep red region,which are suitable to design fluorescent probes with long wavelength emission.Thus,developing some novel probes based on NDIs for heavy metal ions is necessary for the protection of environment and the survival of plants and animals.Chapter one:First,the synthesis approaches of various naphthalene diimides(NDIs)and perylene bisimide(PDIs)derivatives were introduced.Then practical applications of NDIs and PDIs in different fields were described,such as organic field-effect transitors,non-fullenere acceptor in solar cells,fluorescent probes and so on.And some red organic light-emitting diodes based on PDIs were described.At the last,the design thoughts of this thesis were presented.Chapter two:By changing the volume of aromatic substituents linked to core of perylene diimides,the fluorescent properties of PDIs were easily modified from ACQ to AIE.After being fabricated into organic light-emitting diodes,the devices based on these red emitters exhibited good performance with the maximum brightness,current efficiency,power efficiency and the external quantum efficiency of 1948 cd m-2,5.85 cd A-1,2.04 lm W-1,4.93%at a CIE coordinate of(0.56,0.34)?Chapter three:By introducing different volumes of aromatic substituents,from phenyl to carbazole,we obtained four perylene bisimide derivatives,SPhPDI,DPhPDI,SCrPDI and DCrPDI with fluorescent properties changing from ACQ to AIE.Different OLEDs were fabricated based on the four red emitters.Unexpectly,the introduction of carbazole units did not improve the performance of the devices.The doped device based on SPhPDI with 5 wt%showed the best performance with the maximum brightness,current efficiency,power efficiency and external quantum yield of 1484 cd m-2,0.39 lm W-1,1.23 cd A'1 and 1.15%.Chapter four:Unlike normal ACQ-to-AIE conversion by the introduction of aromatic rotors accompanying the realization of a twisted conformation and a prolonged ?-system,the adjustment of the flexible chains could change the fluorescent properties of NDIs from ACQ to AIE,with the tunable packing modes while the original ?-system core and related properties of NDIs remained nearly unchanged,providing an alternative approach for the inhibition of unwanted ?-?stacking.Chapter five:By modifying the amine groups linked to core of naphthalene diimide,we obtained two novel fluorescent probes(NDI-Py,NDI-4)for the detection of Cu2+ with different sensing mechanisms.NDI-Py could serve as a dual-channel colorimetric and fluorescent probe for Cu2+ with the mechanism of intermolecular charge transfer.The probe could not only serve as a“naked-eye”detector for Cu2+ions,but also show "on-off" response to Cu2+ ions.Furthermore,NDI-Py could response to Cu2+ in living cells and silica gel plates.The other fluorescent probe NDI-4 could serve as a "turn-on" fluorescent probe for Cu2+ ions with the mechanism of twisted intramolecular charge transfer,even Cu2+ was inherent paramagnetic.And it could absorb on the silica gel plates to detect Cu2+ ions.Chapter six:Two reversible fluorescent probes(NDI-5,NDI-16)for Hg2+ ions based on naphthalene diimide were obtained with high selectivity and sensitivity.The reversibility with the coordination of KI could be conducted in solution and test stripes for several times.Furthermore,NDI-5 could permeate cell membrane and detect Hg2+ ions in living cells.NDl-16 could serve as a dual-functional probe and be applied as a naked-eye detector for Cu2+.Chapter seven:A novel red fluorescent probe(NDI-15)for the detection of sulfide was designed and synthesized.After addition of Cd2+ ions,the fluorescence intensity of NDI-15 enhanced greatly.Considering that sulfide ions have high affinity to Cd2+ions,a fluorescent probe for S2-ions based on displacement of metal ions was obtained.The probe showed a fast response to S2-ions with high selectivity and sensitivity.Furthermore,NDI-15 could penetrate cell membrane and be applied to detect sulfide ions in HeLa cells.