Organic Light-Emitting Devices (OLED) With Pyrazine Pyrimidine Iridium (Ⅲ) Phosphorescence Materials Research

Ir(â…¢)complexes of heavy metals such elements can have a strong spin-orbit coupling.The original prohibited the triplet state transitions into permitting,Then achieve strong phosphorescence launch,Components can be greatly improved luminous efficiency.This metal ion complexes of Phosphorescence With the ligand structure,luminous great location,This article designed and synthesized of Pyrazine Series organic host ligands and pyrimidine series organic auxiliary ligands,And their iridium(â…¢)Series complexes.And by elemental analysis,melting point determination,NMR methods and so on of synthetic compounds for structural characterization,Use UV-Visible spectroscopy and fluorescence spectroscopy determination of iridium(â…¢)complexes phosphorescence series of absorption spectra and photoluminescence spectroscopy.And summarized the organic ligand molecular structure to the phosphorescent glow material nature influence rule.The papers give the following major conclusions:1.Designed and synthesized the series of pyrazine organic host ligand and the intermediate product.Including:2-methyl-2,3-dihydro-5,6-diphenyl-pyrazine(MDPPH),5-methyl-2,3-diphenyl-pyrazine(MDPP),2,3-dihydro-5,6-diphenyl-pyrazine(DPPH),2,3-diphenyl- pyrazine(DPP), and 2,3-diphenyl-quinoxaline(DPQ),And by melting point determination,elemental analysis,NMR methods and so on of synthetic compounds for structural characterization,The result is the goal product. Through experimental synthesis influence factors determine the optimum reaction conditions.The synthesis series of pyrazine organic host ligand all has the high production rate and the purity.In the optimal reaction conditions,DPP and MDPP production rate respectively is 65%and 76%,DPPH and MDPPH production rate respectively is 69%and 65%,The DPQ production rate is 48%.May provide the organic host ligand for the new phosphorescent glow material metal iridium complexes.2.Through the improvement reaction conditions,one step which designs the synthesis,The successful synthesis of a new type of phosphor material auxiliary Ligand:4-phenyl pyrimidine(PPM), (4-phenyl-fluoroethyl)pyrimidine(FPPM),4-(2,4-difluoro phenyl)pyrimidine(DFPPM).Has proven the process of synthesis rationality.The one step process synthesis has many advantages in the fine chemical synthesis,its synthesis step are few,the side reaction are few,in the experimental process does not need interrupted,the synthesis goal product purity is high,is the ideal synthetic method.Using CuCl for catalyst,inspected the reaction temperature,time,a CuCl/alkone mole of ratio and PH these four factors to the product production rate influence,Has obtained the reaction temperature in the reaction process is a very important influence factor.Conducts the experimental study using the orthogonal testing method to the reaction condition,Obtained the synthesis pyrimidine compounds best reaction condition,In the optimal reaction conditions,The temperature of 170℃,the reaction time was 15 hours,CuCl / ketone the molar ratio of 0.65 and alkalization at pH 10,The synthetic product production rate respectively is:4-phenyl pyrimidine 52%,(4-phenyl-fluoroethyl)pyrimidine 37%,4-(2,4-difluoro phenyl)pyrimidine 36%,And by melting point determination,elemental analysis,NMR methods and so on of synthetic pyrimidine compounds for structural characterization.3.Using CF₃COOAg for catalyst,pyrimidine series organic ligands DPP,MDPP,DPQ has the reaction with IrCl₃-3H₂O,Obtains the final product:Pyrazine series of three ligand metal complexes phosphorescent material——Ir(DPP)₃ is the brown color crystal,the production rate is 12%;Ir(MDPP)₃ is the faint yellow crystal,the production rate is 11%;Ir(DPQ)₃ is the yellowish brown crystal,the production rate is 5.8%.By elemental analysis,NMR and so on to the three synthesis complexes for structural characterization.Had proven designs the process of synthesis is feasible.The experiment will use the response is a dry reaction,before reaction intensive mixing reactant,in reaction process full agitation,the reaction temperature control in 190℃,time is 8h,will be advantageous in enhances the production rate.4.The series of pyrazine organic ligand and the metal iridium reactivity order is:DPP＞MDPP＞DPQ. From the electronic effects and steric effect of space and pyrazine organic ligand structure of the Central line,Discusses several kinds of pyrazine organic ligand and the iridium metallization reaction mechanism.The organic ligand with the iridium reaction primary factor is the electronic effect and the space steric effect.Expanding conjugate system is mainly through the introduction of benzene ring,but in fact is not the introduction benzyl number more the better.This is mainly because the organic ligand and the metal iridium forms through the coordination reaction is one metal complex,Also because of the metal iridium belongs to the 5d⁶ center ion valence electron configuration octahedron structure material,It can only form six coordination bonds,If ligand size too large so then they will certainly have a mutual repulsion,And the ring content are more the angle tensity which its itself link produces to be also bigger,Finally causes the reaction to be very difficult to carry on,or generated complexes is not especially stable.Pyrazine ligand has orphaned to the electron,acts as the electronic donor in this kind of reaction,and the metal iridium ion acts as the role of the electronic acceptor.When the ligand has a pair of electron to shift to the iridium ion hybridization spatial track,The iridium spatial track and the benzene ringÏ€the electronic cloud overlaps,forms a coordination bond,On the metallic ion d orbital electron and the organic ligand spatial counter-key track overlap form feed back the key,finally forms metal five collar organic metallization.5.Through the molecular design,for the first time synthesized two series of new metal complexes phosphorescent material.Pyrazine pyrimidine-iridium(â…¢)complexes:Ir(MDPP)₂Cl(PPM),Ir(MDPP)₂Cl(FPPM),Ir(MDPP)₂Cl(DFPPM)Pyrazine pyridine - iridium(â…¢)complexes:Ir(MDPP)₂(Bpy),Ir(MDPP)₂Cl(Nta),Ir(MDPP)₂(PY), Ir(MDPP)₂Cl(PY-CN),Ir(MDPP)₂Cl[PY-N(NH₃)₂].Using NMR and elemental analysis by means of pyrazine pyrimidine - iridium(â…¢)series and pyrazine pyridine - iridium(â…¢)series of metal complexes of molecular structure characterization.The experimental result indicated the metallized reaction forms is kind of organic metal complex.6.Has determined three series metal complexes which synthesizes:Pyrazine series of three ligand,Pyrazine pyrimidine - iridium(â…¢)series,Pyrazine pyridine - iridium(â…¢)series phosphor materials UV-visible absorption spectroscopy and photoluminescence spectra.The determination result indicated that,each metal complexes all has the very strong ligandπ－π^* and the MLCT jump absorption,¹MLCT and ³MLCT all may distinguish.Designs the spectrum scope which the synthesis the metal complexes may adjust is 545nm-580nm,Also the metal complexes mainly is comes from the metal complexes triplet phosphorescent glow launch in the biggest launch peak place illumination.The explanation may through the change auxiliary ligand chemical Structure,the adjustment metal complexes illumination wave length,(1)Design and Synthesis of new complexes(MDPP)₂Ir(Cl)PPM,This complexes has the strong phosphorescent glow launch under the room temperature in 559nm place.Replaces acetylacetone(acac) with 4- benzyl pyrimidine(PPM)to take the auxiliary ligand,Caused the launch wave length blue to move 21nm.Explained PPM kind of compound is an effective auxiliary ligand,available in Ir(â…¢)series complexes phosphorescent glow material design.(2)Discovery different assistance ligand molecular structure to metal complexes fluorescence wave length influence existence following rule,Has provided the theory basis for the metal complexes phosphorescent glow material in OLED application.a.In the auxiliary ligand substituting group is influential to the metal complexes illumination wave length:When substituents for the exclusion of the electronic group,its fluorescence spectrum has the red shift;When substituents for the electron-withdrawing groups,its fluorescence spectrum has the blue shift;Also attracts the electronic ability to be stronger,its spectrum blue moves obviously.For Metal Complexes,luminescence of the molecular structure of substances and luminescence properties are closely related,May through increase the conjugate system,the increase function member rigidity, carries on methods and so on suitable beautification to the function member to enhance the luminescent material the luminous efficiency.b.In the metal complexes,metal iridium separately with oxygen oxygen atom ?,nitrogen chlorine atom ?,nitrogen nitrogen atoms ? connected,Metal complexes luminescence wavelength blue shift obviously,Therefore,in metal complexes,when host ligand invariable,through the chemical modification auxiliary ligand,may have the remarkable control action to the metal complexes illumination wave length.c.In the metal complexes,the fixed chlorine atom is invariable,when on the pyridine link has attracts the electronic substitution groups,the metal complexes illumination wave length has the blue shift; When on the pyridine link has reprimands the electronic substitution groups,the metal complexes illumination wave length has the red shift.d.In the metal complexes,is all invariable with the iridium connected chlorine atom and the pyrimidine link,only changed with the pyrimidine link connected benzene ring on substituting group,discovered is small to the metal complexes illumination wave length influence,Only plays to this metal complexes illumination wave length the trimming role.