New approaches towards the synthesis and characterization of alkoxy substituted spirobifluorenes and spirosilabifluorenes for organic optoelectronics

Alkoxy substituted spirobifluorene derivatives namely 2,2′,7,7′-tetrabromo-3,6-bis(methoxy)-9,9′spirobifluorene (MSBF), 2,2′,7,7′-tetrabromo-3,6-bis(ethoxy)-9,9′spirobifluorene (ESBF), 2,2′,7,7′-tetrabromo-3,6-bis(butoxy)-9,9′spirobifluorene (BSBF), 2,2′,7,7′-tetrabromo-3,3′,6,6′-tetra(methoxy)-9,9′-spiro-9-silabifluorene (MSSiBF) and their key intermediates have been synthesised successfully. All compounds have been fully characterised by ¹H and ¹³C NMR, FTIR, UV-visible spectroscopy, MS spectrometry. TGA analysis revealed good thermal stability. The systematic investigation on the solubility, thermostability and photophysical property of synthesized compound showed that alkoxy substituted spirobifluorene were unique in rigidity and have wide range of applications in molecular electronics and can be used as building units for optoelectronics material.     

SYNTHESIS AND PHOTOLUMINESCENCE OF AN ANTHRACENE-CONTAINING HYPERBRANCHED POLY（ARYLENEETHYNYLENE）

A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, PL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.     

螺二芴富勒烯吡咯烷衍生物的合成及电化学和光限幅性能

设计合成了3种新颖的螺二芴键联富勒烯(C₆₀/C₇₀)吡咯烷衍生物, 其结构通过IR, ¹H NMR, ¹³C NMR和MALDI-TOF进行确证, 其电化学性质用循环伏安法进行研究. 结果表明, C₇₀衍生物6的还原电位较C₆₀衍生物7分别向负电势移动0.1, 0.12和0.01 V. 同时, 使用纳秒和飞秒激光分别研究了化合物6, 7和8的光限幅性能, 其光限幅阈值分别为15.3, 23.3和13.7 J/cm², 表明材料具有优异的光限幅性能.     

Synthesis of alkylated aminofluorenes by palladium-catalyzed substitution at halofluorenes

New N-substituted 2-amino-9,9-dialkylfluorenes optionally bearing electron-withdrawing substituents such as nitro or cyano in position 7 can be synthesized starting from 2-halo-9,9-dialkylfluorenes by Pd-catalyzed substitution with amines. Chiral amino groups can be introduced by this method too. 2-N,N-Dimethylamino-7-nitro-9H-fluorene was obtained in a convenient way by reductive amination. The N-substituted 2-amino-7-nitro-9H-fluorenes are promising candidates for fluorescence probes for femtosecond solvation dynamics.     

Synthesis and characterization of luminescent organic-inorganic hybrid nanocomposite from polyhedral oligomeric silsesquioxane

<正>A novel polyhedral oligomeric silsesquioxane(POSS)-based organic-inorganic hybrid nanocomposite(EF-POSS) was prepared by Pt-catalyzed hydrosilylation reaction of octahydridosilsesquioxane(T_8H_8,POSS) with a luminescent substituted acetylene(2- ethynyl-7-(4-(4-methylstyryl)styryl)-9,9-dioctyl-9H-fluorene(EF)) in high yield.The hybrid nanocomposite was soluble in common solvents such as CH_2Cl_2,CHCl_3,THF and 1,4-dioxane.Its structure and property were characterized by FTIR, NMR,TGA,UV and PL,respectively.The results show that the hybrid nanocomposite with high thermal stability emits stable blue light as a result of photo excitation and possesses high photoluminescence quantum efficiency(φ_(FL)).     

Syntheses of poly[N-(1-pyrenyl)acetyl ethylenimine] [pyrene-substituted linear poly(ethylenimine)] and poly[methyl 2-(1-pyrenyl)acetamidopropenoate] [pyrene-substituted poly(dehydroalanine methyl ester)]

The syntheses of two new pyrene-containing monomers—2-(1-pyrenyl)methyl-2-oxazoline ( 6 ) and methyl 2-(1-pyrenyl)acetamidopropenoate ( 12 )—and their polymerization are described. Cationic isomerization polymerization of 6 with ethylene glycol ditosylate initiator gave poly[N-(1-pyrenyl)acetyl ethylenimine] ( 7 ) and free-radical polymerization of 12 with AIBN initiator gave poly[methyl 2-(1-pyrenyl)acetamidopropenoate] ( 15 ). The monomer model compounds of the two polymers, namely, N,N-diethyl(1-pyrenyl)acetamide ( 9 ) and methyl 2-methyl-2-(1-pyrenyl)acetamidopropanoate ( 14 ), were also synthesized. The polymers were characterized by elemental analysis, IR spectroscopy, and a comparison of their ¹H-NMR spectra with those of the respective monomer model compounds.     

Röntgenstrukturanalysen von Chiralen Ionophoren: NH4NCS-Komplex von 9,9′-Spirobifluoren-22-Krone-5

X-ray Structure Analyses of Chiral Ionophores: The NH₄NCS Complex of 9,9′-Spirobifluorene-22-crown-5 In the crystalline NH₄NCS complex of 9,9′-spirobifluorene-22-crown-5 ( 1 ) the NH ion sits in the centre of the polyether ring, with distances of 2.92–3.15 Å to the five O-atoms and shows at least twofold orientational disorder. In one orientation, three H-atoms point toward O-atoms and the fourth to the N-atom of the anion situated 2.78 Å above the polyether ring. In another, only two H-bonds are formed. The mean planes of the two fluorene parts of the molecule are perpendicular to each other. Crystals of 2,2′-bis (hydroxymethyl)-9,9′-spirobifluorene ( 2 ), an intermediate for the synthesis of 1 , contain occluded benzene, which cannot be removed under vacuum. X-ray analysis shows that the benzene molecule does not interact with the spirobifluorene in a specific way but merely occupies cages in the crystal packing.     

Efficient greenish blue electrochemiluminescence from fluorene and spirobifluorene derivatives

The spectroscopic and electrochemical behavior as well as electrogenerated chemiluminescence (ECL) of a series of donor-π-donor derivatives bearing triphenylamine groups as donor connected to a fluorene, 2,7-bis-(4-(N,N-diphenylamino)phen-1-yl)-9,9'-dimethylfluorene (1), or spirobifluorene core, 2,7-bis-(4-(N,N-diphenylamino)phen-1-yl)-9,9'-spirobifluorene (2) and 2,2',7,7'-tetrakis(4-(N,N-diphenylamino)phen-1-yl)-9,9'-spirobifluorene (3), were investigated. Besides a high photoluminescence (PL) quantum yield in solution (between 81 and 87%), an efficient radical ions annihilation process induces intense greenish blue ECL emission that could be seen with the naked eye. Only the tetrasubstituted spirobifluorene derivative (compound 3) shows weak ECL obtained by a direct annihilation mechanism. Because the energy of the annihilation reaction is higher than the energy required to form the singlet excited state, the S-route could be considered the pathway followed by the ECL process in these molecules. The ECL emissions recorded by direct ion-ion annihilation show two bands compared to the single structureless PL band. The ECL spectra obtained by a coreactant approach using benzoylperoxide as a coreagent show no differences relative to that produced by annihilation, except for an increasing of ECL intensity for all compounds.     

Substituent effect of fluorine atom on benzothiadiazole bridging unit in dye sensitized solar cells

Dye sensitized solar cells performances using two organic dyes with fluorinated-benzothiadiazole spacer, 3-{5-[7-(5-{4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)-amino]-5-fluoro-phenyl}thiophen-2-yl)benzo-[1,2,5]thiadiazol-4-yl]thiophen-2-yl}-2-cyano acrylic acid (JK-311) and 3-{5-[7-(5-{4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)-amino]-5,6-difluorophe-nyl}thiophen-2-yl)benzo-[1,2,5]thiadiazol-4-yl]thiophen-2-yl}-2-cyano acrylic acid (JK-312), were systematically investigated by solar simulation equipment, stepped light-induced transient measurements of photocurrent and voltage, and electrochemical impedance spectroscopy. To investigate substituent effect of fluorine atom on benzothiadiazole, molecular orbital calculations of two dyes using a time dependent density functional theory model with B3LYP/3-31G* were also carried out. JK-312 showed a unique electronic transition from HOMO-1 to LUMO. Short circuit current and open-circuit voltage in DSSCs performances were increased by the introduction of fluorine atom into spacer segment, compared to fluorine-free dyes.     

The electronic states of polyfluorene copolymers with alternating donor-acceptor units

We calculate the electronic states of the low bandgap polyfluorene-based copolymer DiO-PFDTBT, which consists of alternating 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-ylbenzo[1,2,5]thiadiazole (TBT) units, and compare with the steady-state absorption, emission, and excitation spectrum. Using the semiempirical quantum-chemical (ZINDO) method we can assign the characteristic bands of the "camel-back" absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the pi-conjugated electron system. Additional "dark" charge transfer states in the gap between these bands have been revealed. Calculations are also made on the red light emitting polyfluorene-based copolymer poly(fluorene-co-benzothiadiazole) (F8BT), which contains benzo[1,2,5]thiadiazole instead of TBT. The nature of the electronic states in F8BT and DiO-PFDTBT are found to be qualitatively the same.     

A new class of chiral organogermanes derived from C2-symmetric dithiols: synthesis,characterization and stereoselective free radical reactions

A new class of dithiostannanes and dithiogermanes have been prepared from 1,1'-binaphthyl-2,2'-dithiol and 3,3'-bis(trimethylsilyl)-1,1'-binaphtho-2,2'-dithiol. While reduction of 4-butyl-4-chloro-3,5-dithia-4-stanna-cyclohepta[2,1-a;3,4-a']dinaphthalene to the corresponding tin hydride was unsuccessful, 4-tert-butyl-3,5-dithia-4-germa-cyclohepta[2,1-a;3,4-a']dinaphthalene and 4-tert-butyl-2,6-bis(trimethylsilyl)-3,5-dithia-4-germa-cyclohepta[2,1-a;3,4-a']dinaphthalene were obtained by reduction of the parent germanium chlorides with NaBH(4) and LiBH(4), respectively. Kinetic constants for hydrogen transfer to a primary alkyl radical were measured for both germanium hydrides. Reduction of alpha-halo carbonyl compounds by these germanium hydrides occurs with moderate ee values (up to 42%), while hydrogermylation of methyl methacrylate occurs with low selectivity (<3/1) for the former hydride but high selectivity (>10/1) for the latter.     

Synthesis of 2,2′-diamino-7-tert-butyl-9,9′-spirobifluorene starting from 4,4′-di-tert-butylbiphenyl

Abstract  

A novel spirobifluorene diamine monomer, 2,2′-diamino-7-tert-butyl-9,9′-spirobifluorene, was obtained starting from the readily available reagent 4,4′-di-tert-butylbiphenyl. The key step of the synthesis is the introduction of a nitro group into the 2-position of the spirobifluorene through the loss of tert-butyl at the 2-position.     

一步法合成螺双芴及螺氧杂蒽衍生物及其在有机发光二极管中的应用：性能增强及相关的光学现象关

以芴为原料,以钯为催化剂一步合成了2-(9-苯基芴基)-9,9′螺二芴(PF-SBF)。以PF-SBF作为有机发光二极管的发光及主体材料(FIrpic为磷光客体)时,观察到了不同于PF-SBF及FIrpic发光的红光带。这分别源于PF-SBF分子间的聚集和发光层/传输层诱导的激基复合物。通过选择合适的空穴和电子传输层,有效抑制了激基复合物的发光。同时,PF-SBF和TAPC双主体的结构不仅实现了纯FIrpic和Ir(ppy)3蓝光和绿光,还大幅提升了器件性能。蓝光、绿光器件的最大电流效率和最大亮度分达到16.7、50.5 cd·A^-1和7857 cd·m^-2(11 V)、23390 cd·m^-2(8 V)。另外,除了PF-SBF,利用相似的合成方法,我们也合成了2-(9-苯基芴基)-9,9′螺芴氧杂蒽(PF-SFX),其较大的三线态能级(2.8 eV)较PF-SBF更适合做蓝光主体。以TAPC和PFSFX为双主体的器件最大电流效率提升到了22.6 cd·A^-1。所有实验结果均表明,PF-SBF和PF-SFX是构建高效绿光/蓝光磷光主体材料的有效结构单元。     

9,9′‐spirobifluorene‐containing polycarbonates: Transparent polymers with high refractive index and low birefringence

Syntheses of 2,2′‐bisalcoholic group‐substituted 9,9′‐spirobifluorene monomers 2 were performed by the reaction of 2,2′‐dihydroxy‐9,9′‐spirobifluorene 2a with haloalcohols. Polycarbonates consisting of 9,9′‐spirobifluorene skeleton in the main chain (PC 4 ) were synthesized by the polycondensation of 2,2′‐bisalcoholic monomers 2 and triphosgene or diphenyl carbonate. PC 4 showed good thermal stability: the 5% weight loss temperature was over 330 °C under both nitrogen and air atmospheres. The glass transition temperature was in a range of 16–269 °C estimated by differential scanning calorimetry, depending on the flexibility of the alkylene or oxyethylene chains of 2 . PC 4 showed high solubility toward ordinary organic solvents such as CHCl₃, benzene, and THF, making possible the preparation of the flexible thin films. Very high refractive index in a range of 1.62–1.66 at 589 nm was observed although PC 4 consists only of C, H, and O atoms, whereas very low degree of birefringence was confirmed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3658–3667, 2010     

Oxidative coupling in 4a,9-diaza-1,2,4a,9a-tetrahydrofluorene derivatives. 2. Synthesis of methylenequinoneimines

The oxidative coupling of 4a,9-diaza-1,2,4a,9a-tetrahydro-9H-fluorene derivatives with methylene-active compounds in the presence of MnO₂ leads to substituted (at the methylene group) 6-methylene-4a,9-diaza-1,2,4a,9a-tetrahydro-6H-fluorene derivatives. The corresponding 2,2-disubstituted 5-dicyanomethylene-3,5-dihydrobenzimidozoles were obtained in the reaction of 2,2-disubstituted benzimidazolines with malonitrile in the presence of MnO₂.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 779–785, June, 1990.     

Synthesis of fluorescent fluorene–isoindole-containing mono- and oligomers

Novel fluorene–isoindole-containing light-emitting mono- and oligomers were prepared. The synthesis of the monomers N-(4-bromo-phenyl)-2-(7-bromo-9,9-diethylfluoren-2-yl)-isoindole-1-carboxamide, N-(7-bromo-9,9-dibutylfluoren-2-yl)-2-(7-bromo-9,9-dibutylfluoren-2-yl)-isoindole-1-carboxamide, and N-[7-bromo-9,9-bis(2-ethylhexyl)-fluoren-2-yl]-2-[7-bromo-9,9-bis(2-ethylhexyl)-fluoren-2-yl]-isoindole -1-carboxamide was carried out by a three-component reaction of ortho-phthalaldehyde with the corresponding amine and isocyanide partners. The Ni(0) mediated polymerization reactions of the obtained monomers gave the corresponding mixture of oligomers from two up to twelve repeat units. The optical properties were also studied and it was found that the phenylene-containing oligomer emitted green light in dichloromethane solution, while both difluorene-containing oligomers, under the same conditions, proved to be blue light-emitters with good quantum efficiency.     

Synthesis of novel spiro[indole-3,3′-pyrrolidin]-2(1H)-ones

Diastereoselective [3+2] cycloaddition of azomethine ylide to 1,3-dimethyl-6-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-3a,9a-diphenyl-3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-[1,2,4]triazine-2,7(1H,6H)-dione yields hitherto unknown 1,1′,3-trimethyl-3a,9a-diphenyl-3,3a,9,9a-tetrahydrodispiro(imidazo[4,5-e]thiazolo[3,2-b][1,2,4]triazine-6,3′-pyrrolidine-4′,3″-indole)-2,2″,7(1H,1″H)-triones.     

Anionic cyclization of a cross-conjugated enediyne

Cross-conjugated enediynes cannot follow the Bergman cycloaromatization as it involves a methylenediyne moiety with only five pi e(-), insufficient for aromatization. Under reductive conditions the cyclization is made feasible by generating a product with a Hückel number of pi electrons. We illustrate this principle and demonstrate for the first time an anionic cyclization of a cross-conjugated enediyne that results in formation of a five-membered ring. 9-(3-Phenyl-1-phenylethynylprop-2-ynylidene)-9H-fluorene (3) was reduced by potassium to yield the dianion of 9-(3,4-diphenylcyclopenta-2,4-dienylidene)-9H-fluorene (4(2-)), which contains a cyclopentadienyl fragment, and oxidation with iodine yielded the unstable fulvalene 4.     

An efficient synthesis of novel spiro[[8H]indeno[2,1-b]-thiophene-8,9′-fluorene] building block for blue light-emitting materials

We have developed efficient synthetic routes to obtain a novel building block spiro[[8H]indeno[2,1-b]thiophene-8,9′-fluorene] (SITF), a monothiophene-containing spirobifluorene analogue, and constructed blue light-emitting materials, including 2′,7′-bis([1,1′-biphenyl]-4-yl)-spiro[indeno[2,1-b]thiophene-8,9′-fluorene] (BBP-SITF) and 2′,7′-bis(9,9′-spirobifluoren-2-yl)spiro[[8H]indeno[2,1-b]-thiophene-8,9′-fluorene] (BSBF-SITF). BSBF-SITF has shown to be a stable blue light-emitting material with high PL quantum efficiency (89%) and unique regioselective feature at the C2 of thiophene, which indicate that BSBF-SITF will be useful for constructing complicated optoelectronic systems.     

Highly efficient blue organic light-emitting diodes based on 2-(diphenylamino)fluoren-7-ylvinylarene derivatives that bear a tert-butyl group

Blue fluorescent materials with a 2‐(diphenylamino)fluoren‐7‐ylvinylarene emitting unit and tert‐butyl‐based blocking units were synthesized. The photophysical properties of these materials, including UV/Vis absorption, photoluminescent properties, and HOMO–LUMO energy levels, were characterized and rationalized with quantum‐mechanical DFT calculations. The electroluminescent properties of these molecules were examined through the fabrication of multilayer devices with a structure of indium–tin oxide, 4,4′‐bis{N‐[4‐(N,N‐di‐m‐tolylamino)phenyl]‐N‐phenylamino}biphenyl, 4′‐bis[N‐(1‐naphthyl)‐N‐phenylamino]biphenyl, and blue materials doped in 2‐methyl‐9,10‐di(2‐naphthyl)anthracene/tris(8‐quinolinolato)aluminum/LiF/Al. All devices exhibit highly efficient blue electroluminescence with high external quantum efficiency (3.20–7.72 % at 20 mA cm^?2). A deep‐blue device with Commission Internationale de l’Eclairage (CIE) coordinates of (0.15, 0.11) that uses 7‐[2‐(3′,5′‐di‐tert‐butylbiphenyl‐4‐yl)vinyl]‐9,9‐diethyl‐2‐N‐(3,5‐di‐tert‐butylphenyl)‐2,4‐difluorobenzenamino‐9H‐fluorene as a dopant in the emitting layer showed a luminous efficiency and external quantum efficiency of 3.95 cd A^?1 and 4.23 % at 20 mA cm^?2, respectively. Furthermore, a highly efficient sky‐blue device that uses the dopant 7‐{2‐[2‐(3,5‐di‐tert‐butylphenyl)‐9,9′‐spirobifluorene‐7‐yl]vinyl}‐9,9‐diethyl‐2‐N,N‐diphenylamino‐9H‐fluorene exhibited a luminous efficiency and high quantum efficiency of 10.3 cd A^?1 and 7.7 % at 20 mA cm^?2, respectively, with CIE coordinates of (0.15, 0.20).