Abstract
1,2-Diphenyl-1H-phenanthro[9,10-d]imidazole( PPI),as a model compound for PI-based compound in optoelectronic researches,exhibits good deep-blue emission with high color purity in solid,but has too bad thermal ability to apply as an emitter because its film would break under annealing. Based on the structure-property relationship of PI block,the newborn structure ONBPPI was prepared and confirmed by NMR spectra. It had the same substituted group at C2-position to PPI,and was introduced the ether linkage at N1-phenyl which was different to PPI at N1-position. The analysis of TGA and DSC showed that the thermal ability was enhanced accompany with the molecular weight increase from PPI to ONBPPI. AFM graphs showed that the film of ONBPPI had better stability than PPI in annealing at 90 ℃ for 2 h. And the similar fluorescence spectra in single molecular with fine split delivered that the unchanged transition process existed in both. In the film,a little blue-shift was observed in ONBPPI,which implied that the aggregation effect was weakened because of the ether bond insert. The phenomenon of the proportion of low-energy level emission increase in solid fluorescence spectra was found,but there was no obvious effect on deep-blue color. All of these results were consisted with our expected,and this strategy of enhancing multi-functions on PPI was realized under unchanged transition process by inserting ether linkage at N1-phenyl.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have