Study On The Synthesis,Reduction And Fluoride Ion Detection Properties Of Quinoline And Alkynyl-Substituted Boron-Containing Compounds

Nowadays,boron chemistry has attracted extensive attention from researchers.Boron atoms show extraordinary talents in many fields such as material chemistry,catalytic chemistry and medicinal chemistry due to their unique electron-deficient properties.Boron-containing organic compounds can easily turn into active intermediates(such as boron radicals)when they undergo chemical reactions.However,due to the highly active nature and short life of radicals,it is difficult to stabilize and separate them.Therefore,this has always been a difficult point in scientific research.The reduction of boron-containing compounds and the investigation of their reduction mechanisms are of great significance for us to understand the nature of boron-containing chemical bonds and the formation of boron-containing compounds.Moreover,boron atoms have empty p-orbitals,it's easy for them to form p-?conjugated structures with aryl substituents.Therefore,boron-containing compounds usually have good photophysical properties and attract much attention in the field of optoelectronic materials.When boron-containing organic compounds are complexed with anions(such as Lewis base like fluoride ions),the original p-?conjugate will be destroyed,and the photophysical properties will change.Based on this,triarylborane?arylboronic acid and aryl borate can be excellent choices for the detection and identification of fluoride ions.Based on these main two points,the paper mainly focus on the synthesis,reduction and fluoride ions detection properties of a series of quinoline and alkynyl substituted boron-containing organic compounds.The main tasks are listed as follows:(1)A new type of quinolyl substituted monoboron compounds 1 and 3 and their alkylation products 2 and 4 have been designed and synthesized.Complexes 1-4 were reduced by alkali metals and the EPR of the reduction products were obtained.The electronic and aggregation behavior of reduction products were studied by cyclic voltammetry,X-ray single crystal diffraction,UV-Vis,and DFT calculation.It is preliminarily confirmed that the formation of radicals in the system during the reduction process.And it provides us new ideas for the reduction reaction of boron-containing inner-salt compounds.(2)A new type of alkynyl substituted triaryl monoboron compounds 5 and 7,diboron compounds 6 and 8,boric acid compound 9 have been designed and successfully synthesized.The structure and photophysical properties were characterized and by X-ray single crystal diffraction,UV-visible spectroscopy and fluorescence spectroscopy.Then,the reactions with fluoride ions were explored.Among them,monoboron compound 5,double boron compounds 7 and 8 all exhibit fluorescence enhancement effect,and aryl boronic acid compound 9 can be used as typical fluorescence quenching type F~-probe.They are expected to become a new type of fluoride ion fluorescent probe material.