Theoretical Study On Electronic Spectrum Properties Of 8-Hydroxyquionline Complex

Among many kinds of organic electroluminescent materials, metaloquinolates is becoming a hot research with many advantages such as easy to realize the large screen display, good stability and so on. Especially, 8-hydroxyquionline lithium (Liq), as excellent blue material, has attracted great attention of many researchers while less focus on the effect of substituting group. Especially, the study on double Liq (DLiq) is blank.In this paper, the structures of ground states and excited states, the frontier molecular orbit and the electron spectrum of Liq and its derivates substituted by -CN, -C₆H₅ and -Cl were calculated by means of DFT and TD-DFT methods of Gaussian. The calculation results indicate that the substituting group can adjust emission band. The electron-withdrawing groups on phenol make the electronic spectrum blue shift, while the electron-withdrawing groups on pyriding make the electronic spectrum red shift.In order to study the effect of different kinds of substituting groups on electronic spectrum, Liq's four derivates substituted by -NO₂, -CN, -OH and -CH₃ at position 5 were calculated. The calculation results indicate that the different kinds of substituting group at same position have different effect on the electron spectrum. The electron-withdrawing groups on position 5 make the electronic spectrum blue shift while the electron-releasing groups make the electronic spectrum red shift. The rate of spectral shift is related close to the ability of electron-withdrawing and electron-releasing group of substituting group.At the last part of this paper, double Liq and its two derivates were designed on the basis of the structure of double quinline and its physical and chemical properties were calculated. The calculation results indicate that the electron distribution of the frontier molecular orbit is same as the Liq's. Liq-N₂-Liq has a very strong peak of electronic spectrum which will make it more excellent than Liq as electroluminescent materials. Liq-CH₂-Liq has two strong peaks of electronic spectrum which will make it become new promising duplicated color luminescent materials.The conclusions of this paper is expected to provide a theoretical basis for molecular structure design of the organic electroluminescent materials...