9,9-二(丙酸二甲氨基乙酯)芴共聚物的合成及荧光性能

采用迈克尔加成反应制备了单体2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴(FDMAEA);采用Suzuki偶合反应制备了不同FDMAEA结构单元含量的醇溶性9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物(PFDMAEA)。通过核磁共振、凝胶渗透色谱、溶解性测试、紫外-可见光光谱、荧光发射光谱等对其进行了分析研究。结果表明,成功合成了2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴及9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物。该共聚物在极性溶剂,如甲醇中具有良好的溶解性。由于含有DMAEA支链的PFDMAEA主链容易扭曲,共轭长度变短,共聚物的紫外吸收光谱和荧光光谱随着FDMAEA含量的增加而发生蓝移。荧光发光光谱研究表明,溶剂的极性、溶液的浓度、温度和pH值对共聚物的发光性能有很大的影响。随着溶剂极性增大,共聚物的荧光发射强度不断增加。荧光发射强度随溶液浓度的增加先增加后降低,随着溶液温度的上升而降低。当溶液pH值由1增大到14时,荧光强度不断降低,直至淬灭。     

羟乙基聚芴材料合成与表征

以2,7-二溴-9,9-二(2-羟乙基)-芴和2,7-双硼酸酯-(9,9-二辛基芴)为单体,通过Suzuki聚合反应合成一种蓝光聚(9,9-二羟乙基-2,7-芴)-2,7-(9,9-二辛基芴)(PFOH),采用1HNMR和热重分析对其进行表征,PFOH聚合物具有良好的热稳定性,通过紫外-可见吸收光谱(UV-vis)、光致发光光谱(PL)表征了聚合物的光物理性能,采用循环伏安法通过计算得知聚合物PFOH光学带隙Eg为2.90eV,EHOMO=-5.46eV,ELOMO=-2.56eV。     

蓝光材料双亲共聚芴的合成、表征与性能

通过Suzuki缩聚方法,将单体2,7-二溴-9,9'-二-(3,6-二氧烷基)芴和9,9'-二辛基芴-2,7-二-(三亚甲基硼酸酯)合成了一种新型的蓝光材料-双亲芴基共聚物.采用1H NMR、13C NMR和元素分析对共聚芴结构进行了表征;通过GPC、DSC和TGA测试,共聚芴有较高的分子量和较窄的分子量分布,同时还有很好的热稳定性.对共聚芴的紫外吸收光谱分析表明,在甲苯溶液和薄膜中的波长分别为389nm和393nm;对共聚芴的荧光发射光谱分析表明,在甲苯溶液和薄膜中的波长分别为415nm和437nm.     

新型聚酰亚胺单体螺旋双芴二胺的合成及表征

以联苯和2,7-二溴芴酮为初始原料,经过烷基化、溴代、格氏反应和盖布瑞尔合成,得到了新的螺旋双芴二胺单体,2,7-二胺基-2′,7′-二叔丁基-9,9′-螺二芴(BADBSBF),过程的总收率为28%。该化合物含有两个大的叔丁基以及两个扭曲的芴结构。以它为单体合成的聚酰亚胺有好的溶解性能,从而制备出热稳定、高模量和高强度的纤维。利用傅立叶变换红外光谱(FT-IR)、核磁共振(1H NMR)和质谱(MS)对目标化合物(BADBSBF)的结构进行了分析表征。     

具有深蓝色荧光的分子内电荷转移型三聚体的合成

高效稳有机蓝色荧光材料可以应用于白色光源和全色显示器件。设计合成了具有深蓝色荧光的三聚体3,7-双(9,9-二己基芴基)-2,8-二环己甲氧基-S,S-二氧化二苯并噻吩(FSOCyF)。首先在S,S-二氧化二苯并噻吩(SO)的2,8-位引入官能团环己甲氧基,以增加二苯并氧化噻吩的溶解性,将可溶性的二苯并氧化噻吩溴化后,与9,9-二己基芴-2-硼酸在钯催化下进行Suzuki-coupling反应,合成了分子内电荷转移型三聚体FSOCyF,并运用核磁共振氢谱/碳谱、元素分析、基质辅助激光解吸电离飞行时间质谱,X射线衍射以及荧光光谱对其结构和发光性能进行表征。     

基于芴和噻吩的共轭聚合物的固相合成及其表征

通过Stille偶合反应合成了2,7位二噻吩基取代的新型芴类衍生物并首次应用固相聚合法合成出聚-2,7-二噻吩基芴.在25℃测得聚合物的特性粘度为0.68dl/g.通过核磁共振(1H-NMR)、红外光谱(FTIR)对单体和聚合物的结构进行了表征确认,同时研究了聚合物的光学、结晶态形貌及热学性能.研究发现,2,7-二噻吩基芴在研磨过程中发生了聚合反应且其偶合发生在e,e′位置.     

磺酸型聚芴的合成及性能

利用迈克尔加成反应合成了2,7-二溴-9,9-二-(3-丙基酰胺-2-甲基丙磺酸)芴单体,并通过Suzuki偶合反应制备了含不同磺酸比例的磺酸型聚芴(PF6SO3H)。通过核磁共振氢谱、凝胶渗透色谱、溶解性试验、紫外吸收光谱、荧光发射光谱、循环伏安曲线及热重分析法对聚合物结构和性能进行了表征分析。结果表明,成功合成了相对分子质量在3万~5万之间的磺酸型聚芴。发现随着磺酸型聚芴中磺酸基团含量的不同,聚合物在甲醇溶液中的溶解度不同,含有50%磺酸基团的PF6SO3H在甲醇中的溶解度达到了18mg/mL。磺酸侧链的引入使聚芴在薄膜状态和溶液状态下的紫外吸收最大吸收峰和最大荧光发射峰较聚(9,9-二己基)芴(PF6)发生了9nm~40nm红移,且能带隙逐渐变窄,同时磺酸型聚芴的HOMO较PF6增大。热失重分析发现磺酸侧链的引入,使得磺酸型聚芴的热稳定性较PF6有一定的下降。     

9,9-二(丙酸六氟丁酯)芴共聚物的合成及荧光性能

采用迈克尔加成反应合成了含氟芴单体2,7-二溴-9,9-二(丙酸六氟丁酯)芴(FHFBP),进一步采用铃木反应制备了不同FHFBP结构单元含量的9,9-二(丙酸六氟丁酯)芴-9,9-二辛基芴共聚物(PF8FHFBP)。通过红外光谱、核磁氢谱、紫外光谱和荧光光谱等方法对其结构和性能进行了表征。结果表明,成功合成了相对分子质量较高的含氟聚芴PF8FHFBP,并且在甲苯、四氢呋喃(THF)和氯仿等常用的有机溶剂中具有良好的溶解性。含氟侧链的引入有效地提高了聚合物的疏水性,但使得波长440 nm处聚芴的荧光峰渐渐消失,在530 nm附近出现了1个新的峰。可能是含氟侧链的引入使聚合物侧链产生结晶现象,主链之间更加致密的堆砌产生出激基缔合物,通过不同浓度共聚物溶液的荧光光谱与共聚物的差示扫描量热测试作了进一步分析讨论。     

含芴结构环氧树脂的合成与性能

合成了一种耐湿热性能优异的环氧树脂9,9-二 芴,通过对环氧化反应影响因素的讨论确定了最佳的环氧化反应条件,使产物环氧值达到了理论值的97 ％。确定了纯的9,9-二 芴环氧树脂的固化工艺,并对其树脂浇注料的力学性能进行了评测。为研究9,9-二 芴对其它环氧树脂体系湿热性能的影响,对9,9-二 芴/AG-80树脂体系的吸水率进行了测定,并比较了该体系吸水前后玻璃化转变温度和模量的变化,从而证明了9,9-二 芴对提高环氧树脂耐湿热性能的作用。     

2种苯并咪唑衍生交替共聚物的合成及性能

以苯并噻二唑作为初始原料,通过Sonogashira、Suzuki反应将4,7-二溴-2-己基-1,3-苯并咪唑单体分别与带有不同烷氧基链的对苯乙炔、9,9-二辛基芴进行交替共聚,得到了聚[2-己基-1,3-苯并咪唑-1,4-二乙炔基-2,5-二辛氧基苯](P1)、聚[2-己基-1,3-苯并咪唑-1,4-二乙炔基-2,5-二(十二烷氧基)苯](P2)和聚[2-己基-1,3-苯并咪唑-9,9-二辛基芴](P3)。采用红外光谱、核磁共振等手段对单体和共聚物的结构进行了表征,利用紫外-可见吸收光谱、荧光量子效率测试和循环伏安法对聚合物的光、电化学性能进行了探讨。结果表明,共聚物P1、P2均在445 nm处出现紫外-可见吸收峰,共聚物P3在376 nm处出现紫外-可见吸收峰。P2、P3共聚物的相对荧光量子效率分别为80%,66.7%,所得共聚物都有较强的荧光性能。P2共聚物在1.3 V处出现氧化掺杂峰,在-1.3 V处出现还原掺杂峰,P3共聚物在0.48 V处出现氧化掺杂峰,0.34 V处出现脱掺杂峰。     

Toward the extraction of single species of single-walled carbon nanotubes using fluorene-based polymers

High purity of (7,5) SWNTs (approximately 79% of the semisonducting SWNT ensemble) can be obtained by polymer-assisted extraction from the narrow-diameter distributed SWNTs produced by the catalyst Co-MCM-41. The fluorene-based polymers are able to selectively wrap the single-walled carbon nanotubes (SWNTs) with certain chiral angles or diameters depending on their chemical structures. Poly(9,9-dioctyfluoreny1-2, 7-diyl) and poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(9,10-anthracene)] selectively wrap SWNTs with high chiral angles (>24.5 degrees). By contrast, poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,1'-3}-thiadiazole)] preferentially wraps the SWNTs with certain diameter (1.02-1.06 nm).     

Excited-state absorption and anisotropy properties of two-photon absorbing fluorene derivatives

The electronic structure of fluorene derivatives N-(7-benzothiazol-2-yl-9,9-bis-decyl-9H-fluoren-2-yl)-acetamide (1); 9,9-didecyl-2,7-bis-(N,N-benzothiazoyl)fluorene (2); 4,4'-{[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl}bis(N,N-diphenyl)benzeneamine (3); and 4,4',4"{[9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2,1-ethenediyl}tris(N,N-diphenyl)benzeneamine (4) were investigated by a steady-state spectral technique, quantum-chemical calculations, and a picosecond pump-probe method. These derivatives are of interest for their relatively high two-photon absorption. The steady-state excitation anisotropy spectra reveal the nature of the ground-state absorption bands. Semiempirical quantum-chemical calculations of the fluorene derivatives (AM1, ZINDO/S) show good agreement with experimental data. The spectral positions and alignment of various electronic transitions of derivatives 1-4 were estimated from their excited-state absorption and anisotropy spectra.     

Structure and optical properties of single crystal of fluorene–thiophene oligomers

Solid-state optical properties of polymorph 2,7-(2-thienyl)-9,9-dihexylfluorene [TFT(C6)₂] and 2,7-di(2-thienyl)-9,9-cyclopentanefluorene [TFT] related to their crystal structure are reported. 3D phase of the first molecule displays a very peculiar arrangement, tetragonal system, where adjacent molecules cannot face to each other, due to fourfold alternating axis, therefore preventing close intermolecular interactions. The 3D packing of the second molecule shows a herringbone arrangement, where dimers are alternatively shifted. Both exhibit significant photoluminescence (PL), which changes in position and shape as a function of the solid state organization. Such different arrangements are related to different PL quantum yield values preliminarily determined.     

Blue electroluminescent materials based on 2,7-distyrylfluorene for organic light-emitting diodes

A series of blue fluorescent 9,9-diethyl-2,7-distyryl-9H-fluorene derivatives with various capping moieties such as diphenylamino; diphenylphosphino; triphenylsilyl; phenoxy; phenylmercapto; phenylselenoxy; and triphenymethyl groups were synthesized using the Honor-Emmons reaction. The highest occupied molecular orbital-lowest unoccupied molecular orbital energy levels were characterized with a photoelectron spectrometer and rationalized with quantum mechanical density functional theory calculations. The electroluminescent properties were explored through the fabrication of multilayer devices with a structure of Indium-tin-oxide/N,N′-diphenyl-N,N′-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine/2-methyl-9,10-di(2-naphthyl)anthracene:blue dopants (5-15 wt.%)/4,7-diphenyl-1,10-phenanthroline/lithium quinolate/Al. All devices, except that using NPh₂, exhibited a Commission Internationale de I'Eclairage (CIE) y value less than 0.19. The best luminous efficiency of 3.87 cd/A and external quantum efficiency of 2.65% at 20 mA/cm² were obtained in a device comprising the 4-phenylsulfanyl capped 9,9-diethyl-2,7-distyrylfluorene derivative with CIE coordinates (0.16, 0.18).     

Systematic approach of blue-light-emitting copolymers by introducing various naphthalene linkages into fluorene containing PPV derivatives

We newly synthesized a series of naphthalene and fluorene containing alternating copolymers, poly[9,9-n-dihexyl-2,7-fluorenediylvinylene-alt-1,4-naphthalenevinylene] (1,4-PNFPV), poly[9,9-n-dihexyl-2,7-fluorenediylvinylene-alt-2,6-naphthalenevinylene] (2,6-PNFPV), and poly[9,9-n-dihexyl-2,7-fluorenediylvinylene-alt-2,3-naphthalene-vinylene] (2,3-PNFPV) through the well known Wittig polycondensation reaction. The conjugation lengths of the polymers were controlled by differently linked naphthalenes in the polymer main chain. The resulting polymers were completely soluble in common organic solvents and exhibited good thermal stability up to 400 °C. The synthesized polymers showed UV–visible absorbance and photoluminescence (PL) in the ranges 352–379 and 465–512 nm, respectively. The maximum emission peak of 1,4-PNFPV was found at 512 nm with green light. But, 2,6- and 2,3-PNFPV showed more blueshifted blue PL emission than that of 1,4-PNFPV at 477 and 465 nm, respectively. This result showed that 2,3- and 2,6-naphthalene linkage of the 2,3- and 2,6-PNFPV reduced π-conjugation length compared to 1,4-naphthalene linkage of the 1,4-PNFPV. The single-layer light-emitting device was fabricated which has a simple ITO (indium–tin oxide)/polymer/Al configuration. Electroluminescence (EL) maxima of 1,4-PNFPV and 2,6-PNFPV were shown at 523 and 484 nm, respectively. The measurement of current vs. electric field showed the threshold voltages of 1,4-PNFPV and 2,6-PNFPV to be about 1.7×10⁸ and 2.1×10⁸ V/m. The EL powers of 1,4-PNFPV and 2,6-PNFPV were reached 36 and 24 cd/m² at 2.3×10⁸ V/m (206 mA/cm²) and 2.8×10⁸ V/m (190 mA/cm²), respectively.     

Molecular design of copolymers based on polyfluorene derivatives for Bulk-heterojunction-type solar cells

Poly{[2,7-(9,9′-dihexylfluorene)]-alt-[4,7-di(thiophen-2-yl)benzo[c][1, 2, 5]thiadiazole]} (PFDTBT) with low band gap was reported as an intriguing and promising donor in Bulk-heterojunction-type solar cells. In this paper, based on the structure of PFDTBT, three new kinds of donor materials: poly{[2,7-(9,9′-dihexylfluorene)]-alt-[4,7-di(thiophen-2-yl)-[1, 2, 5]thiadiazolo[3,4-d]pyridazine]} (PFDTTDP), poly{[2,7-(9,9′-dihexyloxyfluorene)]-alt-[4,7-di(thiophen-2-yl)-[1, 2, 5]thiadiazolo[3,4-d]pyridazine]} (POFDTTDP), and poly{[2,6-(4,4-dihexyl)-4H-cyclopenta[2,1-b;3,4-b’]-dithiophene)-alt-[4-(1,3,4-thiadiazol-2-yl)-7-(thiophen-2-yl)-[1, 2, 5]thiadiazolo[3,4-d]pyridazine]} (PCPTTTDP), were designed and computed by density function theory (DFT). The electronic, optical and photovoltaic properties, and charge transport rates were investigated. The reorganization energies for holes and electrons are around 0.11 and 0.08 eV, respectively. It indicates that PFDTTDP, POFDTTDP, and PCPTTTDP are good candidates for donor material. Especially, when 6,6-phenyl-C61-butyric acid methyl ester (PC₆₁BM) functions as acceptor, PCPTTTDP has the most appropriate highest occupied molecular orbital and lowest unoccupied molecular orbital energy, and has the broadest absorption in the near-infrared region.     

Polymeric white organic light-emitting diodes with two emission layers

A white light-emitting diode was fabricated by preparing multilayer emitting films with an inserted buffer layer. The device structures are ITO/PEDOT:PSS/Emissive layer/LiF/Al. The emissive layer comprises a yellow-emitting layer of Poly[9,9-dioctylfluorenyl-2,7-diyl]-co-1,4-benzo-(2,1,3)-thiadiazole (F8BT), a blue-emitting layer of Poly[9,9-di-(2'-ethylhexyl)fluorenyl-2,7-diyl] (BEHF) and PEDOT:PSS as a buffer layer between the emission layers. The solution processed multi-layer polymer light-emitting diodes (PLED) were prepared by introduction of a water-soluble buffer layer between organic solvent soluble layers. We present white organic light-emitting diodes (WOLEDs) that has bilayer emission zones. This device exhibits a brightness of 280 cd/m2 and emission efficiency of 1.18 cd/A at 12.6 V. The device with a doped PEDOT:PSS layer and a thicker blue-emission layer exhibits CIE color coordinates of (0.30, 0.34), which is close to the white coordinates of (0.33, 0.33) used by the standard CIE color coordinates.     

Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N'-(4-butylphenyl)-bis-N, N'-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.     

Photo- and electroluminescence properties of fluorene-based copolymers containing electron- or hole-transporting unit

We report the photophysical and electroluminescence (EL) properties of two fluorene-based copolymers, poly{[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl]-alt-[6,6′- bis(3-phenylquinoxaline)-2,2′-diyl]} (Qx-PF) and poly{[9,9-bis(2- ethylhexyl)fluorene-2,7-diyl]-alt-[N,N′-diphenyl-N,N′-bis(4-phenyl)-1,1′-biphenyl-4,4′-diamine]} (TPD-PF). The two copolymers in thin films show blue emission approximately 429-452 nm with relatively narrow bandwidth upon photoexcitation. Electroluminescence has been demonstrated using TPD-PF as the active polymer in the light-emitting electrochemical cell (LEC) with a turn-on voltage at 2.8 V and an EL efficiency of 0.002 cd/A. Due to the improved electron-transporting property, the Qx-PF-based LEC achieves the EL efficiency of 0.07 cd/A, 35 times higher than that of the TPD-PF-based device. Compared to the photoluminescence spectra, EL spectra show enhanced excimer emission, which is primarily related to self-heating of the devices during operation. The main process involved in the decrease of the light intensity during device operation is the electrochemical degradation of the polymer blend.