β-二酮类铱配合物的合成、表征及光电性能测试

以5-甲基-2-苯基吡啶（CH3ppy）为主配体，3,7-二乙基-4,6-壬二酮（detd）、2,2,6,6-四甲基-3，5-庚二酮（tmd）和乙酰丙酮（acac）为辅助配体（LX），设计合成了三种含-二酮类辅助配体的绿色磷光金属铱配合物（Ⅲ,Ⅳ,Ⅴ）。通过1HNMR和元素分析对其结构进行了表征，通过UV-vis光谱和荧光发射光谱（PL）测得化合物Ⅲ、IV、V的最大吸收波长范围在250 nm~280 nm之间，最大发射波长分别为530.8 nm、534.2 nm和524.8 nm。制备了器件结构为：ITO/HAT-CN (15nm)/TAPC (50nm)/TCTA (5nm)/TCTA:X (8%,15 nm)/Bepp2 (35nm)/LiF (1nm)/Al (150nm)的有机发光二极管（OLEDs）。结果表明，以化合物Ⅲ制备的器件亮度可以达到59125.2 cd/m2，最大外量子效率为15.0%，最大电流效率为53.8 cd/A，最大功率效率为62.1 lm/W，色坐标（0.30，0.62），是三个器件中综合性能最好的。     

两种新型磷光金属铱配合物的合成及光电性能研究

以3-甲基-1-(2-氟苯基)咪唑和3-甲基-1-(4-氟苯基)咪唑作为第一配体,2-甲酸吡啶作为第二配体,合成了以铱(III)为内核的两种有机电致磷光材料(o-fpmi)2Ir(pic)(o-fpmi=3-甲基-1-(2-氟苯基)咪唑,pic=2-甲酸吡啶)和(fpmi)2Ir(pic)(fpmi=3-甲基-1-(4-氟苯基)咪唑)。通过核磁1H NMR和液相质谱LC-MS对其结构进行分析确认,并用紫外-可见吸收光谱、荧光发射光谱和循环伏安法测定其光电物理性能,热重分析测定铱配合物的热稳定性。结果表明,(fpmi)2Ir(pic)和(o-fpmi)2Ir(pic)的紫外吸收峰值为231,270,300,360 nm和237,281,315,370 nm,最大荧光发射波长为502 nm和508 nm,主要来源于三重态3MLCT的辐射跃迁,热分解温度为300℃,是一类热稳定性好的蓝绿色发光材料。     

一种绿色铱磷光配合物的合成及性能研究

以3-苯基苯硼酸、2-溴吡啶为原料,通过与三氯化铱的配合反应,合成了一种绿色有机电致磷光材料[二(2-联苯基吡啶)](2-吡啶甲酸)合铱(Ir(bppy)2pic),通过1H NMR、质谱对其进行了结构表征。并对配合物的紫外吸收和发光性能进行考察,研究表明其在405 nm和475 nm处存在单重态1MLCT和三重态3MLCT的吸收峰;最大发射波长为503 nm,是一种具有更加饱和的发射光谱的绿色磷光材料。     

新型黄光铱磷光配合物的合成、表征及性能研究

通过在2,4-二氯吡啶上引入3-联苯基,合成了一种以2,4-二(3-联苯)吡啶为主配体,以2,2,6,6-四甲基-3,5-庚二酮为辅助配体的新型有机电致磷光材料,通过元素分析、红外光谱、~1H NMR和质谱对产物进行了结构表征,利用X射线单晶衍射仪测定了配合物的晶体结构。并对其用紫外-可见吸收、光致发光、热稳定性等进行研究。研究表明,配合物在395和465nm处存在单重态~1MLCT(金属到配体的电荷跃迁)和三重态~3MLCT的吸收峰;其初始分解温度为405℃(对应于10%质量损失),最大发射波长为570nm,是一种可用于白色有机电致发光器件的新型黄色发光磷光材料。     

铱配合物磷光探针的合成及细胞荧光成像

磷光铱配合物具有良好的光热稳定性、发光颜色可调性、较长的激发寿命和较高的发光效率等特点。以2-苯基并噻唑衍生物(含有醛基、乙氧基和叔丁基)为主配体、1,10-邻菲罗啉为辅助配体,合成3个磷光铱配合物。通过核磁共振谱和高分辨质谱对其结构进行表征,利用荧光光谱和紫外-可见吸收光谱对其发光性能进行研究,并测试了磷光铱配合物的细胞荧光成像作用。     

β-二酮类铱配合物的合成、表征及光电性能

以5-甲基-2-苯基吡啶(CH3ppy)为主配体,3,7-二乙基-4,6-壬二酮(detd)、2,2,6,6-四甲基-3,5-庚二酮(tmd)和乙酰丙酮(acac)为辅助配体(LX),设计合成了3种含β-二酮类辅助配体的绿色磷光金属铱配合物(Ⅲ、Ⅳ、Ⅴ)。通过1HNMR和元素分析对其结构进行了表征,通过UV-Vis光谱和荧光发射光谱(PL)测得化合物Ⅲ、Ⅳ、Ⅴ的最大吸收波长范围在250～280 nm,最大发射波长分别为530.8、534.2和524.8 nm。制备了3种有机发光二极管(OLEDs)。结果表明,以化合物Ⅲ制备的器件亮度可以达到59125 cd/m2,最大外量子效率为15.0%,最大电流效率为53.8 cd/A,最大功率效率为62.1 lm/W,色坐标(0.30,0.62),在3个器件中综合性能表现最好。     

一种铱磷光配合物的合成表征及性能研究

利用2-苯基吡啶(ppy)、三水合氯化铱(IrCl_3·3H_2O)和2-吡啶甲酸(pic)配位,得到铱配位物Ir(ppy)_2pic,合成产率9 0%,该方法适合于Ir(ppy)2pic的批量制备。通过元素分析、核磁共振(~1H-NMR、~(13)C-NMR)和质谱(MS)对产物分子结构进行了表征,此外结合紫外吸收光谱(UV-Vis)和荧光光谱(PL)对其光物理性能进行了研究。结果表明:该配合物在紫外谱图上的250~300 nm处出现了强的配体单重态π-π*自旋跃迁吸收峰,在400~500 nm处出现了铱(Ш)到配体的单重态和三重态(~1MLCT和~3MLCT)电子跃迁吸收峰,在荧光光谱的514 nm处有较强的金属配合物三重态的磷光发射峰,显示为一种高效的绿色磷光材料。     

带烷氧基的苯基蒎烯吡啶铱配合物在聚合物电致发光器件中的应用研究

采用旋涂法将一组带烷氧基的苯基蒎烯吡啶铱（Ⅲ）配合物（It（ROPPPY）3）磷光材料掺杂到PVK中,制作出了聚合物电致发光器件：ITO／PEDOT：PSS（40nm）／PVK0.7：PBD0．3：（x％．）Ir—complex（80nm）／CsV（1．5nm）／Mg：Ag（200nm）．实验结果表明,带有长烷氧基链配体的铱（Ⅲ）配合物能表现出更好的器件行为,当掺杂浓度为3．2％时,器件的最高发光效率达19．9cd／A（7．8lm／W,9．1V）,CIE为（0．20,0．56）;器件最大亮度为15700cd／m^2（8．4V）．通过对这组铱（Ⅲ）配合物的光物理行为及电化学性能的研究,考察了主体材料与配合物之间的能级配置以及能量转移的机理、     

新型喹喔啉铱（Ⅲ）配合物的微波合成及其光致发光

采用微波辐射方法,由2-苯基喹喔啉（PQ）与水合三氯化铱（IrCl3·H2O）反应,合成了一种新型三环喹喔啉铱配合物[Ir（PQ）3]（PQ=2-苯基喹喔啉）,通过^1HNMR、元素分析和质谱方法对配合物进行了表征,并研究了配合物的紫外吸收光谱和光致发光光谱。结果表明,配合物Ir（PQ）3在476nm和607nm处存在单线态。MLCT（金属到配体的电荷跃迁）和三线态。MLCT的吸收;在625nm处有较强的金属配合物三线态的磷光发射,是一种新型红色三线态磷光材料。     

发光有机器件用新型荧光掺杂材料的合成及表征

对具有代表性的绿色磷光发光掺杂材料Ir(ppy)3[三(2-苯基吡啶)合铱]进行了改性,在其配位体处导入了含有较大空间位阻的芳香族置换基团;设计开发了具有空穴/电子传导部位的EL(有机电致发光)共聚物,并分别对改性后的磷光掺杂材料[如Ir(Bu-ppy)3(三丁基吡啶合铱配合物)、Ir(Cz-ppy)3(三咔唑吡啶合铱配合物)等]与导电高分子掺杂后制成的OLED(有机发光二极管)的性能进行了分析。研究结果表明:上述芳香族置换基团能减轻浓度消光效应,提高原有掺杂材料的发光效率,并且提高了含该掺杂体的高分子材料在有机溶剂中的溶解性;含Bu-ppy配位结构的磷光掺杂材料比含Cz-ppy配位结构的掺杂材料具有更高的器件效率。     

Triazole and Pyridine Hybrid Molecules as Electron-Transport Materials for Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes

A series of triazole and pyridine hybrid molecules, with a triazole core and pyridine periphery, were designed and synthesized as an electron-transport layer (ETL) and a hole/exciton-block layer for green phosphorescent organic light-emitting diodes. Compared with the widely-used electron-transport material (ETM) of 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ) with a triazole core, lower-lying HOMO and LUMO energy levels were obtained with the introduction of pyridine rings onto the periphery of the molecules, giving improved electron injection and carrier confinement. Significantly reduced driving voltages were achieved in a device structure of ITO/HATCN (5 nm)/TAPC (40 nm)/CBP:8 wt % Ir(PPy)₃ (10 nm)/ETL (40 nm)/LiF (1 nm)/Al (90 nm), giving a maximum power efficiency of 72.2 lm W⁻¹ and an external quantum efficiency of 21.8 %, due to the improved electron injection and transport and thus, more balanced carrier recombination, which are much higher than those of the device based on TAZ.     

Synthesis and characterization of a new iridium(III) complex with bulky trimethylsilylxylene and applications for efficient yellow-green emitting phosphorescent organic light emitting diodes

We designed and synthesized a new iridium(III) complex with phenylpyridine ligands containing a bulky trimethylsilylxylene, 5-(2,5-dimethyl-4-(trimethylsilyl)phenyl)-2-phenylpyridine, by Suzuki coupling reaction and characterized using various spectroscopic studies. Nuclear magnetic resonance studies show its structure to be that of a facial isomer. Thermogravimetric analysis and differential scanning calorimetry studies show its higher thermal stability (?T_5%) of 638 K with a glass transition temperature of 425 K. It shows the photoluminescence emission at 532 nm in solution with the band gap energy of 2.56 eV. The new iridium(III) complex as dopant in phosphorescent organic light emitting diodes exhibits the yellow-green emission at 532 nm as it effectively hinders aggregation formation in the solid state at a dopant concentration of 6%, resulting in higher device efficiencies of 12.7% and 45.7 cd/A. The results show that the new iridium complex could be useful in white organic light emitting diodes for the lighting applications.     

Synthesis and device performance of an oxygen‐interrupted bipolar polymer host with carbazole and triphenylphosphine oxide in the main chain

A novel bipolar polymer host PC10CzPO, carrying hole‐transporting carbazole and electron‐transporting triphenylphosphine oxide units in the oxygen‐interrupted main chain, was synthesized and characterized. In addition to its excellent thermal stability and miscibility with phosphors, PC10CzPO is also reported to have a triplet energy (E_T) as high as 2.83 eV due to oxygen‐interrupted π‐conjugation, ensuring that PC10CzPO can be used as a suitable host material. The PC10CzPO‐based phosphorescent devices were investigated and compared, while doping with typical blue phosphor {iridium(III)[bis(4,6‐difluorophenyl)pyridinato‐N, C2]picolinate, FIrpic)}, green phosphor {tris[2‐(p‐tolyl)pyridine]iridium(III), Ir(mppy)₃}, and red phosphor [bis(1‐phenyl‐isoquinoline‐C2,N)(acetylacetonato)iridium(III), Ir(piq)₂acac]. As a result, the FIrpic‐based blue devices showed better device performances than those of red and green devices, which was ascribed to more effective energy transfer. This indicates that the choice of proper host and dopant emitters to fabricate phosphorescent polymer light emitting diodes (PhPLED) is a simple and effective approach to optimize device performances. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44461.     

Efficient white polymer-light-emitting-diodes based on polyfluorene end-capped with yellowish-green fluorescent dye and blended with a red phosphorescent iridium complex

A novel series of blue and yellowish-green light-emitting single polymers were prepared by end-capping of low contents of 4-bromo-7H-benzo [de]naphtha[2′,3′:4,5]imidazo[2,1-a]isoquinolin-7-one (M1) into polyfluorene. Electroluminescence (EL) spectra of these polymers exhibit blue emission (λ_max = 430/460 nm) from the fluorene segments and yellowish-green emission (λ_max = 510/530 nm) from the M1 units. For the polymer (PFNAP-0.06) with the M1 unit content of 0.06 mol-%, its EL spectrum shows balanced intensities of blue emission and yellowish-green emission with Commission Internationale de l'Eclairage (CIE) coordinates of (0.25, 0.34). The maximum brightness of the device prepared from the polymer (PFNAP-0.06) is 6704 cd/m² at 10 V with a structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) [PEDOT:PSS]/PVK/emission layer/Ca/Ag. A new white polymer-light-emitting-diode (WPLED) can be developed from the single polymer (PFNAP-0.06) system blended with a red phosphorescent iridium complex [Bis(2-[2′-benzothienyl)-pyridinato-N,C^3′] iridium (acetylacetonate) (BtpIr)]. We were able to obtain a white-light-emission device by adjusting the molar ratio of BtpIr to PFNAP-0.06 with a structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) [PEDOT:PSS]/PVK/emission layer/Ca/Ag. The brightness in such a device configuration is 4030 cd/m² at 9 V with CIE coordinates of (0.32, 0.34).     

Phosphorescent,green-emitting Ir(III) complexes with carbazolyl-substituted 2-phenylpyridine ligands: Effect of binding mode of the carbazole group on photoluminescence and electrophosphorescence

The ligands, 9-((6-phenylpyridin-3-yl)methyl)-9H-carbazole and 9-(4-(pyridin-2-yl)benzyl)-9H-carbazole were synthesized by attaching a carbazolyl group to the pyridine and phenyl rings of 2-phenylpyridine, respectively. Ir(III) complexes were prepared by a simple procedure and the solubility of the novel complexes was significantly better than that of the conventional, green-emitting conventional fac-tris(2-phenylpyridinato-C²,N)iridium(III). The Ir(III) complexes were used to prepare electrophosphorescent polymer light-emitting devices. The device comprising 10% of fac-tris(2-(4′-((9H-carbazol-9-yl)methyl)phenyl)pyridinato-C²,N)iridium(III) exhibited an external quantum efficiency of 7.88%, luminous efficiency of 23.01 cd/A, and maximum brightness of 32,640 cd/m². The color of the emissions of fac-tris(2-(4′-((9H-carbazol-9-yl)methyl)phenyl)pyridinato-C²,N)iridium(III) was similar to that of conventional fac-tris(2-phenylpyridinato-C²,N)iridium(III). This work shows that integration of a rigid hole-transporting carbazole and phosphorescent complex in one molecule provides a new route to highly efficient, solution-processable complexes for electrophosphorescent applications.     

Novel yellow phosphorescent iridium complexes containing a carbazole–oxadiazole unit used in polymeric light-emitting diodes

Yellow iridium complexes Ir(PPOHC)₃ and (PPOHC)₂Ir(acac) (PPOHC: 3-(5-(4-(pyridin-2-yl)phenyl)-1,3,4-oxadiazol-2-yl)-9-hexyl-9H-carbazole) were synthesized and characterized. The Ir(PPOHC)₃ complex has good thermal stability with 5% weight-reduction occurring at 370 °C and a glass-transition temperature of 201 °C. A polymeric light-emitting diode using the Ir(PPOHC)₃ complex as a phosphorescent dopant showed a luminance efficiency of 16.4 cd/A and the maximum external quantum efficiency of 6.6% with CIE coordinates of (0.50, 0.49). A white polymeric light-emitting diode was fabricated using Ir(PPOHC)₃ which showed a luminance efficiency of 15.3 cd/A, with CIE coordinates of (0.39, 0.44). These results indicate that the iridium complexes containing a linked carbazole–oxadiazole unit are promising candidates in high-efficiency electroluminescent devices.     

Novel yellow phosphorescent iridium complexes containing a carbazole-oxadiazole unit used in polymeric light-emitting diodes

Yellow iridium complexes Ir(PPOHC)₃ and (PPOHC)₂Ir(acac) (PPOHC: 3-(5-(4-(pyridin-2-yl)phenyl)-1,3,4-oxadiazol-2-yl)-9-hexyl-9H-carbazole) were synthesized and characterized. The Ir(PPOHC)₃ complex has good thermal stability with 5% weight-reduction occurring at 370 °C and a glass-transition temperature of 201 °C. A polymeric light-emitting diode using the Ir(PPOHC)₃ complex as a phosphorescent dopant showed a luminance efficiency of 16.4 cd/A and the maximum external quantum efficiency of 6.6% with CIE coordinates of (0.50, 0.49). A white polymeric light-emitting diode was fabricated using Ir(PPOHC)₃ which showed a luminance efficiency of 15.3 cd/A, with CIE coordinates of (0.39, 0.44). These results indicate that the iridium complexes containing a linked carbazole-oxadiazole unit are promising candidates in high-efficiency electroluminescent devices.     

Supramolecular Phosphorescent Polymer Based on Cationic Iridium Complexes for Polymer Light-Emitting Diodes

Three novel orange emission supramolecular phosphorescent polymers (SPPs) with cationic iridium complex have been developed for polymer light-emitting diodes (PLEDs) through efficient self-assembly. The supramolecular assembly process was monitored by ¹H nuclear magnetic resonance (¹H NMR) and viscosity measurement. These SPPs give orange phosphorescence with a peak at about 595 nm and display good thermal properties with a glass-transition temperature (T_g) about 90 °C. The single-emissive-layer PLEDs with charged SPPs exhibited the highest device efficiency of 2.81 cd A^?1 with the Commission Internationale de L’Eclairage coordinates of (0.58, 0.40). The present work reported the charged SPPs self-assembled by the cationic iridium complex for the first time and provided a new guide to develop orange emitters for solution-processable optoelectronic devices.

     

Miscibility study on blend of thermotropic liquid crystalline polymers and polyester

The miscibility of thermotropic liquid crystalline polymers (TLCPs) and polyester blends was investigated with thermal and morphological analyses, as well as transesterification. TLCPs composed of 80 mol % para‐hydroxybenzoate (PHB) and 20 mol % poly(ethylene terephthalate) (PET) or 60 mol % PHB and 40 mol % PET, and polyesters such as PET and poly(ethylene 2,6‐naphthalate) (PEN) were melt blended in an internal mixer. DSC analyses were performed to investigate the thermal transition behavior and to obtain thermodynamic parameters. All the blends showed only a single glass‐transition temperature, which means they are partially miscible in the molten state. The Flory–Huggins interaction parameter was calculated employing the Nishi–Wang approach, and negative values were obtained except for the P(HB8‐ET2)/PEN blends. Transesterification was investigated using ¹H‐NMR, and the change of chemical shift compared to pure PET or P(HB‐ET)s was observed in the P(HB‐ET)/PET blends. An intermediate chemical shift value (4.83 ppm) was observed in the P(HB6‐ET4)/PEN blends, which indicates transesterification occurred. The fractured surface morphology of scanning electron micrographs showed that the interfaces between the LC droplets and matrix were not distinct. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1842–1851, 2003     

Synthesis,Aggregation-Induced Emission,and Electroluminescence of Dibenzothiophene- and Dibenzofuran-Containing Tetraarylethenes

Dibenzothiophene- and dibenzofuran-functionalized ethanes were synthesized by the McMurry coupling reaction. The luminogens are faintly emissive when molecularly dissolved in good solvents, but emit intensively when aggregated as nanoparticles in poor solvents or fabricated as solid thin films, demonstrating the phenomenon of aggregation-induced emission (AIE). Their organic light-emitting diode (OLED) applications were explored, utilizing the AIE effect. Electroluminescence devices with the configuration of indium tin oxide (ITO)/N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB; 60 nm)/dye (20 nm)/1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi; 10 nm)/tris(8-hydroxyquinoline)aluminum (Alq₃; 30 nm)/LiF (1 nm)/Al (100 nm) were fabricated. The OLED device emits at 510 nm with a maximum luminescence and external quantum efficiency of 10⁴ cd/m² and 2.1 %, respectively. The OLED behavior of the E/Z isomers was also studied.