The Studies On Synthesis,Reduction And Photophyscial Properties Of Alkynyl/Alkenyl-bridged Boron-containing Compounds

In 1986,P.P.Power the first reported tricoordinated boron anion radical.Since then,the synthesis and stabilization of boron radicals has become one of the emerging research areas in recent decades.There are potential applications in organic synthesis,biomedicine,functional materials.In recent years,the research on boron radicals have mainly focused on structural studies,but their reactivity has been less studied.In response to the above problems,this paper conducts the following research:First,we have synthesized a series of di-cycloborate olefin complexes 2 and 4 from alkynyl bridged diboryl compounds using a simple reduction strategy.Their geometric and photophysical properties were characterized by UV-vis,NMR,Single crystal X-ray,Fluorescence spectroscopy,Elemental analysis together with theoretical DFT calculation,the formation mechanism of compounds 2 and 4 was deeply explored.It is result that the reduction reaction undergoes the cyclization of radicals,the leaving of naphthalene groups,the configuration inversion,and finally the intramolecular cyclization.Second,we have synthesized a series of alkennyl bridged boron-containing compounds,such as monoboryl compounds and diboryl compounds.First,the monoboron compounds 6 and 7 were reduced and ⁿBu₃SnH was used to capture the radicals to obtain an anionic compound 8,its geometric was characterized by Single crystal X-ray and Elemental analysis.Second,the synthesis of six alkenyl-bridged compounds were reduced,but the corresponding anionic compounds were not obtained.Subsequently,their photophysical properties was consequently investigated,in conjunction with DFT calculations.As the result of HOMO and LUMO orbital energy gap were changed by increasing the conjugacy of the system and adjusting the position of the boron unit,the photophysical properties of alkenyl-bridged compounds were changed.