Study On The Synthesis,Reduction,and Photophysical Properties Of Phenyl-bridged Diboryl Compounds

Boron-containing organic compounds have attracted extensive attention in the fields of coordination chemistry,catalytic chemistry,and electro-optical material chemistry because of their unique electron-deficient features.Boron atoms can capture electrons to turn into radical intermediates when the boron-containing organic compounds undergo chemical reductions.Due to the radical intermediates have high activity,and they are unstable greatly,so they can change boron organic compounds with new electronic structure or chemical bond after going through some chemical reactions.The studies of these reduction reactions are helpful to understand the nature of boron-containing chemical bonds,and it is great significance for further exploration of the corresponding chemical reactions and the geometrical and electronic configurations of the compounds.Meanwhile,in organic photoelectric materials such as organic light-emitting diodes,organic photovoltaic cells and other fields,the introduction of boron-containing organic compounds is helpful to enhance the fluorescence of materials and improve the conductivity of materials.Based on this,this paper mainly focus on the synthesis,reduction and photophysical properties of phenyl-briged diboron-based organic compounds.The main tasks are listed as follows:（1）A new type of dis-boron organic compound 1 with triphenylbenzene as the bridging group that has a central symmetry without planar symmetry has been designed and synthesized,and the effect of its unique spatial configuration on the reduction result is also investigated.Diboryl organic compound 1 underwent successive reduction,free radical-cyclization and oxidative-dehydrogenation to generate the free radical intermediate[1··]^2-,reduction products 1a,1b,and the final thermodynamic stability product 2a.Through the characterization of the reduction products in each stage and the theoretical calculation,the changes of the spectra and structure of the compounds during the reaction were revealed,and the reduction mechanism was systematically explained.（2）Based on the study of the second chapter,a number of diboryl compounds 7-10with different bridging groups were designed and synthesized.And the photophysical properties of these compounds in solution and solid state were studied.Compounds 8-10and 1 show a strong blue fluorescence at about 440-450 nm.They possess good electron affinity and expect to be a new type of boron-containing organic materials.