Synthesis, two-photon absorption and AIE properties of multibranched thiophene-based triphenylamine derivatives with triazine core

Two new multibranched thiophene-based triarylamine derivatives with 1,3,5-triazine core are synthesized and characterized. Their one-and two-photon absorption properties and aggregation-induced emission effect have been investigated. Both the STAPA-based compounds are AIE active. The two-photon absorption (2PA) cross sections measured by the open aperture Z-scan technique are determined to be 620 and 1610 GM for STAPA-a and STAPA-b in chloroform,respectively, which dramatically increase with the introduction of alkyl chains. The relationship between their structures and properties on one-and two-photon absorption and aggregation-induced emission is discussed, which allows us to examine the effect of introducing alkyl chains. In addition, solvent effects also show a significant influence on the 2PA cross section. The two compounds with excellent AIE and 2PA properties provide attractive alternatives for the biophotonic materials.     

Synthesis and photophysical properties of tetraphenylethylene-based conjugated dendrimers with triphenylamine core

Two new conjugated dendrimers bearing a tetraphenylethylene moiety as dendrons and triphenylamine as a core have been synthesized through a convergent synthetic strategy using threefold Heck/threefold Sonogashira coupling reaction. These dendrimers showed excellent solubility in common organic solvents and emit light in the blue and violet regions.     

Theoretical investigations on electronic structures and photophysical properties of novel bridged triphenylamine derivatives

It has been proved that triphenylamine (TPA) derivatives can be excellent candidates for hole‐transporting materials in organic light‐emitting diodes (OLEDs). To improve on the thermal and morphological stability, a fully diarymethylene‐bridged TPA derivative (FATPA) which has been proven to enhance electroluminescent (EL) efficiency was synthesized. On the basis of FATPA, two series of novel bridged TPA derivatives have been designed by using diarylmethylene (Series A) or dimethyfluorene (Series B) as the linkage between the ortho‐positions of the phenyl rings in this work (see Fig. 1 ). To reveal the relationships between electronic structures and photophysical properties of these novel functional materials, an in‐depth theoretical investigation was elaborated via quantum chemical calculations using the density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) methods. In addition, the feasibility of using these bridged TPA derivatives as host in the device of ITO/MoO₃/NPB/mCP/host:Ir(ppy)₃/TAZ/LiF/Al was also evaluated, which including the discussion to their energy levels match with adjacent layers and energy transfer from host to guest. These calculated results show that photophysical properties can be easily tuned by the introduction of various substituent groups into the bridged TPA derivatives, such as the highest occupied molecular orbitals (HOMOs), the lowest unoccupied molecular orbitals (LUMOs), the energies difference between the HOMOs and LUMOs (Δ_H‐L), the lowest singlet (E_S) and triplet (E_T) excitation energies, ionization potentials (IPs), electron affinities (EAs), reorganization energies (λ) and the absorption and emission spectra, indicating that these bridged TPA derivatives have great potential applications for OLEDs. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012     

Synthesis and photophysical properties of novel pyrimidine-based two-photon absorption chromophores

Three new two-photon absorption chromophores based on a pyrimidine core were synthesized by Aldol condensation in the absence of any organic solvents. Their single-photon spectroscopic characterization as well as their two-photon absorption properties is reported. In addition, strong modulation of single-photon and two-photon fluorescent spectra of these molecules by (de)protonation is also discussed.     

Multi-carbazole derivatives for two-photon absorption data storage:Synthesis,optical properties and theoretical calculation

Two novel quadrupolar organic compounds, 3-(4-((E)-2-(9-butyl-9H-carbazol-6-yl) vinyl)styryl)-9-propyl-9H-carbazole (BCSPC) and 3-(3-(3-((1E)-2-(4-((E)-2-(3-(3,5-bis(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazol-6-yl)vinyl)phenyl) vinyl)-9-butyl-9H-carbazol-6-yl)-5-(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazole (BCPBC), with different conjugated arms, have been designed and synthesized. Their one-and two-photon absorption (TPA) and excited fluorescence properties have been experimentally inve...     

Multi-carbazole derivatives for two-photon absorption data storage: Synthesis, optical properties and theoretical calculation

Two novel quadrupolar organic compounds, 3-(4-((E)-2-(9-butyl-9H-carbazol-6-yl) vinyl)styryl)-9-propyl-9H-carbazole (BCSPC) and 3-(3-(3-((1E)-2-(4-((E)-2-(3-(3,5-bis(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazol-6-yl)vinyl)phenyl) vinyl)-9-butyl-9H-carbazol-6-yl)-5-(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazole (BCPBC), with different conjugated arms, have been designed and synthesized. Their one- and two-photon absorption (TPA) and excited fluorescence properties have been experimentally investigated. The two-photon absorption cross-sections of two compounds were estimated by two-photon excited fluorescence technique using 200 fs, 76 MHz, Ti:sapphire laser, which are 22 and 154 GM for BCSPC and BCPBC, respectively. The optimal excitation wavelengths are 780 nm for both BCSPC and BCPBC. A data recording experiment proved the potential application of the materials.     

Synthesis and photophysical properties of phenyl-sulfanylated chlororophyll derivatives

Chlorophyll derivatives that possessed a phenylsulfanyl group at the C3¹- or C3²-position were synthesized and their optical properties were investigated. Methyl 3¹-phenylsulfanyl-mesopyropheophorbide-a was prepared by substitutions of the corresponding C3¹-hydroxy-chlorin, methyl bacteriopheophorbide-d, with thiophenol in the presence of zinc iodide or of the corresponding C3¹-bromo-chlorin with thiophenol. The regioisomeric C3²-phenylsulfanyl-chlorin was obtained by addition of thiophenol to the C3-vinyl group of methyl pyropheophorbide-a in the presence of AIBN. Both the synthetic compounds gave similar electronic absorption and emission spectra in chloroform, but fluorescence quantum yield of the C3¹-sulfanyl-chlorin (0.18) was ca. 30% smaller than those of the C3²-sulfanyl-chlorin (0.25) and the C3-ethyl-chlorin (0.24). These observations were consistent with their fluorescence lifetime data. It is suggested that the heavy atom effect of a sulfur atom at the C3¹-position can tune photophysical properties of the chlorophyll derivatives.     

Synthesis of new two-photon absorbing fluorene derivatives via Cu-mediated Ullmann condensations

The Ullmann amination reaction was utilized to provide access to a number of fluorene analogues from common intermediates, via facile functionalization at positions 2, 7, and 9 of the fluorene ring. Through variation of amine or iodofluorene derivative, analogues bearing substitutents with varying electron-donating and electron-withdrawing ability, e.g., diphenylamino, bis-(4-methoxyphenyl)amine, nitro, and benzothiazole, were synthesized in good yield. The novel fluorene derivatives were fully characterized, including absorption and emission spectra. Didecylation at the 9-position afforded remarkably soluble derivatives. Target compounds 4, 5, and 9 are potentially useful as fluorophores in two-photon fluorescence microscopy. Their UV-vis spectra display desirable absorption in the range of interest suitable for two-photon excitation by near-IR femtosecond lasers. Preliminary measurements of two-photon absorption indicate the derivatives exhibit high two-photon absorptivity, affirming their potential as two-photon fluorophores. For example, using a 1,210 nm femtosecond pump beam, diphenylaminobenzothiazolylfluorene 4 exhibited nondegenerate two-photon absorption, with two-photon absorptivity (delta) of ca. 820 x 10(-50) cm(4) s photon(-1) molecule(-1) at the femtosecond white light continuum probe wavelength of 615 nm.     

Synthesis, crystal structures, and photophysical properties of triphenylamine-based multicyano derivatives

A new series of intramolecular charge transfer (ICT) molecules were synthesized by attaching various strong electron-withdrawing groups to a triphenylamine backbone. Relationships between chemical structures and optoelectronic properties of these compounds were investigated with X-ray diffraction, cyclic voltammetry, absorption spectroscopy, and density functional theory calculations. It is shown that the compounds exhibit intensive ICT interactions leading to substantial extension of their absorption spectral response, which may be potentially used for efficient solar cells.     

Synthesis, characterization and photophysical properties of novel tetrasubstituted phthalocyaninato zinc derivatives

Peripherally tetraimido-substituted phthalocyaninato zinc compounds 1-3 were synthesized through the reaction of tetraamino-substituted phthalocyaninato zinc with 4-Br-1,8-naphthalic anhydride, 4-hexahydropyridine-1,8-naphthalic anhydride and 4-morpholine-1,8-naphthalic anhydride, respectively. The compounds were characterized by MS, ¹H NMR, UV-vis, IR and elemental analysis, the results of which were consistent with the proposed structures. The effects of substitutes, acid/base and solvents on the UV-vis spectra of the new complexes were discussed in detail.     

Synthesis of nicotinonitrile derivatives and study of their photophysical properties

Abstract  

A convenient route was developed for the synthesis of novel nicotinonitrile derivatives by a three-component Dimroth reaction of chalcones, malononitrile, and secondary heterocyclic amines or sodium alcoholate. Nicotinonitrile derivatives are obtained in fair to good yields. The structures of all new compounds were established by spectroscopic characteristics and their photophysical properties were studied.     

Synthesis of triphenylamine-cored dendritic two-photon absorbing chromophores

[structure: see text]. A new series of dendritic two-photon absorbing chromophores containing triphenylamine moiety as a core or branching points have been synthesized through a convergent synthetic strategy. One-photon and two-photon optical properties of these molecules were characterized. In the nanosecond time domain, these molecules exhibited large two-photon absorption (TPA) cross sections up to 7.56-12.2 x 10(-44) s cm(4) at 800 nm, indicating that these molecular structures were viable candidates for various two-photon related applications.     

Novel aromatic polymers from benzaldehyde and triphenylamine derivatives: Synthesis,electrochromic, and photochemical properties

A series of novel triphenylamine‐based polymers were synthesized from benzaldehyde and triphenylamine derivatives. All the polymers having high molecular weight are readily soluble in many organic solvents and could be solution‐cast into amorphous films. They had glass transition temperatures (T_gs) in the range of 193–217 °C, and 10% weight loss temperatures in excess of 475 °C. Cyclic voltammograms of all polymers showed reversible oxidation redox peaks and E_onset around 0.42–0.90 V, indicating that the polymers are electrochemically active and stable. In addition, all these polymers revealed photochemical characteristics in conformity with their electrochromic characteristics. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2118–2131, 2009     

Copolyfluorenes containing bridged triphenylamine or triphenylamine: Synthesis,characterization, and optoelectronic properties

A novel aryl‐bridged triphenylamine derivative, 7‐t‐butyl‐5,5,9,9‐tetraaryl‐13b‐aza‐naphtho[3,2,1‐de]anthracene (ABTPA) was designed and synthesized. The alternating copolymers of ABTPA/dihexylfluorene ( P1 ) and triphenylamine (TPA)/dihexylfluorene ( P2 ) were synthesized by Suzuki coupling reaction. P1 shows excellent thermal stability with a decomposition temperature of 440 °C and a glass‐transition temperature of 326 °C. The HOMO energy levels of the two polymers are very close (?5.15 eV for P1 and ?5.13 eV for P2 ). The maximum absorption peak of P1 is red shifted by 23 nm with respect to P2 , because the incorporation of ABTPA units into the PF backbone enhances the electronic conjugation degree compared with the case of TPA units. The rigidity and the steric hindrance of the ABTPA in P1 result in a small Stokes shift and almost the same emission spectra of P1 between its film and solution. A PLED with simple configurations of ITO/ P1 /TNS (tetranaphthalen‐2‐yl‐silane)/Alq₃ (tris(8‐hydroxyquinolinolato)aluminum)/Al emits a blue light with emission peak at 436 nm, and exhibits a maximum current efficiency of 1.89 cd/A and a maximum luminance of 4183 cd/m², which is superior to the device with P2 as emissive layer under the identical conditions. These results indicate that ABTPA unit could be a very promising candidate to replace TPA unit and find widely application in organic/polymeric optoelectronic materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3651–3661, 2009     

Synthesis and properties of polythiophene derivatives containing triphenylamine moiety and their photovoltaic applications

A series of novel soluble polythiophene derivatives containing triphenylamine moiety were synthesized by Grignard metathesis (GRIM) method. The structures of the polymers were characterized and their physical properties were investigated. High molecular weight (M_n up to 25,800 g/mol) and thermostable polymers were obtained. The absorption spectra demonstrated that the absorption wavelength of the polymers could be tuned dramatically by introducing thiophene units in the main chain of the polymers. Photoluminescence spectra indicated that there was intramolecular energy transfer from the side chain to the main chain, and the maximum emission was red‐shifted gradually with the increase of thiophene units in the main chain. Cyclic voltammetry displayed that the polymers possessed relatively high oxidation potential, which promised good air stability and high open circuit voltage for photovoltaic cells application. Finally, bulk heterojunction photovoltaic devices were fabricated by using the polymers as donors and (6,6)‐phenyl C₆₁‐butyric acid methyl ester (PCBM) as acceptor. The maximal open circuit voltage of the photovoltaic cells reached 0.71–0.87 V and the power conversion efficiencies of the devices were measured between 0.014% and 0.45% under white light at 100 mW/cm². © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3970–3984, 2008     

Synthesis, photophysical and photochemical properties of aryloxy tetra-substituted gallium and indium phthalocyanine derivatives

The synthesis, photophysical and photochemical properties of the tetra-substituted aryloxy gallium(III) and indium(III) phthalocyanines are reported for the first time. General trends are described for photodegradation, singlet oxygen, fluorescence, and triplet quantum yields and triplet lifetimes of these compounds. The introduction of phenoxy and tert-butylphenoxy substituents on the ring resulted in lowering of fluorescence quantum yields and lifetimes, and triplet quantum yields, and an increase of k_IC, k_ISC, and k_F. Photoreduction of the complexes was observed during laser flash photolysis. The singlet oxygen quantum yields (Φ_Δ), which give an indication of the potential of the complexes as photosensitizers in applications where singlet oxygen is required (Type II mechanism) ranged from 0.41 to 0.91. Thus, these complexes show potential as Type II photosensitizers.     

新型双光子吸收化合物的合成、光物理及其在固态分散体系中的性质

通过多步反应制备了三个新型的双光子吸收化合物,测试了它们的光物理性质,发现该系列化合物具有较大的双光子吸收截面,并且随温度降低其双光子吸收截面增大.尤其是化合物TMVDB,其量子效率为0.83,常温时的双光子吸收截面达到1164GM,其双光子吸收截面除以分子量为2.08,表现出了优良的双光子吸收发光性能.进一步将TMVDB掺杂到固体材料中,得到强双光子诱导发光的固体材料.     

Synthesis, photophysical and electroluminescent properties of novel naphthalimide derivatives containing an electron-transporting unit

A series of naphthalimide derivatives containing a benzoazole unit (benzothiazole, benzoxazole or benzimidazole) as electron-transporting unit was designed and synthesized, and their photophysical and electroluminescent properties were investigated. The key design of molecular structures included the use of carrier-transporting fragments, together with twisted molecular conformation that could eliminate the recrystallization tendency and favour the formation of a stable amorphous state. ITO/NPB/emissive layer/Mg∶Ag/Ag bilayer electroluminescent devices were fabricated. Green or yellow-green electroluminescence was obtained successfully with peak emission in the range 530–560 nm.     

Synthesis and photophysical properties of long wavelength absorbing BODIPY/aza-BODIPY bearing a five-membered ring

Five-membered-ring fused BODIPYs and aza-BODIPY were herein prepared. X-ray crystallographic analysis revealed that the core skeleton of six-membered-ring fused BODIPY is nonplanar but twisted. Such five-membered-ring fused BODIPY/aza-BODIPY dyes have long wavelength absorptions/emissions, high extinction coefficients, peak fluorescence and narrow excitations/emissions. MO calculations well supported and explained the same absorption maxima between BODIPY bearing the five-membered ring and BODIPY bearing the six-membered ring.