Stepwise Nanosynthesis Of Fluorene-based Oligogrids With Amplified Spontaneous Emission

Electromechanically pumped lasers have not yet been realized,so it is important to study the relationship between different materials and reveal the molecular structure of their gain medium and laser characteristics.In addition to side chain effect,few reports were stated related to shape effect and gridization effect.In view of this,a series of sterically hindered multi-arm oligomers,“?”-shaped gridarene and fused digridarene of different shapes and lengths have been synthesized,and their structures have been characterized,and the ASE characteristics have been tested.Details as follows:Firstly,In order to study the gridization effect,less research on the structure-activity relationship of sterically hindered multi-arm oligomers of different shapes and lengths,we first studied the opening of H-shape oligofluorene.For photoelectric performance,we successfully synthesized H-shape/X-shape molecules through C-C coupling reaction and tested their ASE performance.The results show that the performance of X-shape is better than that of H-shape.However,for the study of the arm length,the performance decreases along with the arm lengths increased.Secondly,“?”-shaped gridarenes are a known unit grid,and we have synthesized a single substrate of A1-B1 type by a stepwise method.Compared with the L-type substrate,the yield of cyclization increased from 21% to 95%.We have also been fortunately isolated Grid-DFCz-1,Grid-DFCz-2,and Grid-DFCz-3.We have basically fixed their configurations as Trans-1-Grid,Cis-Grid,and Trans-2-Grid by NMR characterization methods and so on.In order to study the isomers and gridization effect,we tested their optoelectronic properties.The results showed that there were no obvious isomers and gridization effect.Thirdly,fused digridarene are also a known juxtaposed grid structure.We synthesized a single substrate of type A2-B2 type by a stepwise method.Compared with the H-type substrate,the yield of cyclization increased from 9-26% to 95%.Through NMR and other characterization,its structure was determined,and its ASE performance was tested.The ASE threshold of the“?”-shaped gridarene was 3.59 ?J/cm2,exhibiting excellent ASE performance.In order to study the effect of gridization,we tested its basic photoelectric performance and ASE performance,the results also showed no obvious gridization effect.