Herein,two compounds,4-2′-hydroxybenzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-1)and 4-benzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-2),were synthesized to explore the hydrogen bonding effect on mechanoresp...Herein,two compounds,4-2′-hydroxybenzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-1)and 4-benzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-2),were synthesized to explore the hydrogen bonding effect on mechanoresponsive luminescent(MRL).The results showed that compound BN-1 exhibited strong emission in solution and solid-state compared with compound BN-2.After grinding,the emission intensity of compound BN-1 sharply decreased by as much as 15 times with an obvious red-shift from 552 nm to 577 nm.The control compound BN-2,by contrast,did not change so much before and after grinding.Single crystal analysis suggests that BN-1 molecule formed strong intramolecular interaction via-N=N⋯H-O hydrogen bond with a distance of 0.2632 nm.An excited-state intramolecular proton transfer(ESIPT)based fluorophore featured this intramolecular hydrogen bond.The intramolecular hydrogen bond as well as other intermolecular interactions can rigidify the molecular conformation of compound BN-1 in solid-state,and thus suppress the nonradiative pathways,resulting in strong emission.These intra-and intermolecular interactions were destroyed by mechanical stimuli,accompanied by molecular conformation change that decreases the luminescence and blocks the ESIPT process.The MRL process was also demonstrated by scanning electron microscopy and powder X-ray diffraction.The molecular stacking mode changed from crystalline to a disordered amorphous state after grinding.展开更多
Naphthalimide derivatives, N-ethyl-4-acetylamino-l,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-1,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices ...Naphthalimide derivatives, N-ethyl-4-acetylamino-l,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-1,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices of ITO/PVK(120nm)/EAAN(50nm)/Al(150nm) (I) and ITO/PVK+ P-PhAN(10:1) (50nm)/Al( 150nm) (II) constructed with EAAN and P-PAAN as the emitting layer were investigated, whereas the single-layer devices of ITO/EAAN or P-PAAN(50nm)/Al(150nm) (III) were not observed to have any e-mission light. The emission results revealed that the exaction recombination formed by positive and negative charge carriers injected from electrodes of devices I and II was much more balanced than that of devices III, which implied that naphthalimide derivatives are a new type of electron-transporting materials with high performance. The electron-transporting properties of naphthalimide derivatives were also elucidated by investigation of the electroluminescent behaviors from both devices of ITO/PPV (80nm)/Al and ITO/PPV (80nm)/EAAN (20)nm)/Al hch fabricated with EAAN as the electron-transporting layer.展开更多
基金supported by the National Natural Science Foundation of China(No.21301126)the Natural Science Foundation of Shanxi Province,China(Nos.2013021009-3,201701D221038)the Scientific and Technological Innovation Programs of Higher Education and Institutions in Shanxi Province(STIP),China(No.2017128).
文摘Herein,two compounds,4-2′-hydroxybenzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-1)and 4-benzylidenehydrazinyl-N-butyl-1,8-naphthalimide(BN-2),were synthesized to explore the hydrogen bonding effect on mechanoresponsive luminescent(MRL).The results showed that compound BN-1 exhibited strong emission in solution and solid-state compared with compound BN-2.After grinding,the emission intensity of compound BN-1 sharply decreased by as much as 15 times with an obvious red-shift from 552 nm to 577 nm.The control compound BN-2,by contrast,did not change so much before and after grinding.Single crystal analysis suggests that BN-1 molecule formed strong intramolecular interaction via-N=N⋯H-O hydrogen bond with a distance of 0.2632 nm.An excited-state intramolecular proton transfer(ESIPT)based fluorophore featured this intramolecular hydrogen bond.The intramolecular hydrogen bond as well as other intermolecular interactions can rigidify the molecular conformation of compound BN-1 in solid-state,and thus suppress the nonradiative pathways,resulting in strong emission.These intra-and intermolecular interactions were destroyed by mechanical stimuli,accompanied by molecular conformation change that decreases the luminescence and blocks the ESIPT process.The MRL process was also demonstrated by scanning electron microscopy and powder X-ray diffraction.The molecular stacking mode changed from crystalline to a disordered amorphous state after grinding.
文摘Naphthalimide derivatives, N-ethyl-4-acetylamino-l,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-1,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices of ITO/PVK(120nm)/EAAN(50nm)/Al(150nm) (I) and ITO/PVK+ P-PhAN(10:1) (50nm)/Al( 150nm) (II) constructed with EAAN and P-PAAN as the emitting layer were investigated, whereas the single-layer devices of ITO/EAAN or P-PAAN(50nm)/Al(150nm) (III) were not observed to have any e-mission light. The emission results revealed that the exaction recombination formed by positive and negative charge carriers injected from electrodes of devices I and II was much more balanced than that of devices III, which implied that naphthalimide derivatives are a new type of electron-transporting materials with high performance. The electron-transporting properties of naphthalimide derivatives were also elucidated by investigation of the electroluminescent behaviors from both devices of ITO/PPV (80nm)/Al and ITO/PPV (80nm)/EAAN (20)nm)/Al hch fabricated with EAAN as the electron-transporting layer.