| This paper focus on the development of new thiophene boron doped organic conjugated system,mainly divided into two parts: the first part is the study on synthesis and properties of thiophene-fused 1,4-thiaborins;the second part is the study of properties of dibenzo thiophene fused 1,4-thiaborins.These boron-containing polycyclic aromatic hydrocarbons were successfully synthesized,and the physical and chemical properties of the compounds were fully studied.The details are as follows:In the first part,thiophene-fused 1,4-thiaborins Ⅰ-1 and Ⅰ-2 were designed and synthesized.Initially,boron/tin exchange reaction was used as the key step to synthesize the target compounds.Later on,we improved the synthetic route in order to avoid using of toxic tin reagents.The X-ray structure was obtained by diffusion method.Then combined with the theoretical calculation,we found that the aromaticity of the central 1,4-thiaborin ring can be enhanced by replacing of the benzene rings with thiophenes.In addition,we also studied their photophysical properties.Morevoer,we found that the 2,4-position of Ⅰ-1 and Ⅰ-2 can be functionalized by deprotonation/electrophile quench reaction,further functionalization by Stille coupling reaction was employed to synthesize the 2,6-diphenyls thiophene-fused 1,4-thiaborins.We found that the absorption and emission spectra of the resulting deriviatives were red shift compared to the parent thiophene-fused 1,4-thiaborins.Finally,we found that the absorption and emission of Ⅰ-1 and Ⅰ-2 can be inhibited after adding excess F-,which demonstrated that the Lewis acidity of boron in Ⅰ-1 and Ⅰ-2 remians intact.In the second part,benzothiophene-fused 1,4-thiaborins Ⅱ-1 and Ⅱ-2 were designed and synthesized,using the similar route.The X-ray crystals of the two isomers were obtained by solw diffusion of hexane into their corresponding concentrated dichloromethe solution.Subsequently,we studied their absorption,emission spectra and their binding ability with F-.We also recorded cyclic voltammetry of Ⅱ-1 and Ⅱ-2.We found that the photophysical properties of these two isomers are quite different.In addition,Ⅱ-1 and Ⅱ-2 are stable to air and moisture.In summary,two kinds of polycyclic aromatic hydrocarbons containing 1,4-thiaborins was studied,and the relationship between their structures and properties were investigated.We hope the research will pave the way for these type of PAHs in optoelectronic materials. |
