Triarylamines with branched multi-pyridine groups： modulation of emission properties by structural variation, solvents,and tris(pentafluorophenyl)borane

Six triarylamine derivatives 1–6 with branched multi-pyridine substituents were prepared and characterized. These compounds are distinguished by the substituent on one of the phenyl group with NO2 for 1, CN for 2, Cl for 3, p-C6 H4 OMe for 4, OMe for 5,and NMe2 for 6, respectively. As revealed by single crystal X-ray analysis, these substituents play an important role in determining the configuration of the triarylamine framework and the crystal packing of 1–6. The emission properties of these compounds were examined in different solvents(toluene, CH2 Cl2, acetone, tetrahydrofuran(THF), and N,N-dimethylformamide(DMF)) and in solid states. Distinct dual emissions from the localized emissive state and the intramolecular charge transfer state were observed for compound 5 in CH2 Cl2. Compounds 1 and 6 show apparent aggregated enhanced emissions in acetone/H2 O.The emission properties of these compounds were further modulated by the addition of tris(pentafluorophenyl)borane. In addition, density functional theory(DFT) and time-dependent DFT(TDDFT) calculations have been performed on the ground and singlet excited states to complement the experimental findings.

Efficient Synthesis of Triarylamines Catalyzed by Copper(I)Diazabutadiene Complexes

Cuprous chloride was coordinated by diazabutadiene(DAB-R)ligands to form Cu(I)-(DAB-R)complexes,most of which have a 1∶1 ratio of Cu to DAB-R as reported.In the case of a special DAB-iPP,N,N'-bis(2,6-diiso-propylphenyl)-1,4-diaza-1,3-butadiene,an unexpected composition of complex was found with the formula Cu(I)Cl(DAB)_(2).When employed as catalyst for triarylamine synthesis from the coupling of aryl halides with pri-mary and secondary arylamines,the new Cu(I)-(DAB-iPP)complex displayed high efficiency.

Influence of Triarylamine and Indoline as Donor on Photovoltaic Performance of Dye-Sensitized Solar Cells Employing Cobalt Redox Shuttle

Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.

Syntheses and Crystal Structures of Two New Compounds Containing Triarylamine and Benzoic Hydrazide Units

Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) ? b = 11.046(4) ? c = 24.335(9) ? b =92.649(7), V = 2502.7(16) ?, Z = 4, m = 0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367 observed reflections with I > 2s(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) ? b = 24.138(10) ? c = 10.398(4) ? b = 104.913(8), V = 2579.8(17) ?, Z = 4, m = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2s(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.

Synthesis and Characterization of Triarylamine-Based Block Copolymers by Combination of C-N Coupling and ATRP for Photorefractive Applications

Poly(4-butyltriarylamine)s with t-butyldimethylsilyl terminal protecting group (PBTPA-TBS) with various molecular weights were prepared by C-N coupling polymerization. The resulting precursors were postfunctionalized and subse- quently used as macroinitiators for atom transfer radial polymerization (ATRP) of n-butyl acrylate (n-BA) and ethyl acrylate (EA). Both the polymerization processes were controlled and the polymers were characterized by 1H NMR, gel permeation chromatography (GPC) and thermal properties, which confirmed the successful synthesis of all the poly-mers. The microphase separated behaviors of the poly (4-butyltriarylamine)-block-poly (butyl acrylate) (PBTPA-b-PBA) were examined by AFM in the film showing phase separation structures for all the polymers. The photorefractive property of the composite based on PBTPA-b-PBA block copolymer was evaluated by two-beam coupling experiment. A relative high gain coefficient of 42.7 cm?1 was obtained at the electric field of 31 V/?m.

Synthesis and Crystal Structure of (p-{2-[p-(5'-Phenyl-1',3',4'-oxadiazole-2'-yl)-phenyl]- vinyl}-phenyl)-di-p-tolyl-amine

The crystal of the title compound (C36H29N3O,Mr = 519.62) has been prepared and structurally determined by X-ray single-crystal diffraction. It crystallizes in triclinic P space group with the crystal cell parameters: a = 12.544(4), b = 14.112(4), c = 17.770(5)? = 96.150(6), = 106.112(5), = 107.156(5)? V = 2825.7(14) 3, Z = 4, Dc = 1.221g/cm3, (MoK? = 0.074 mm-1 , F(000) = 1096,the final R = 0.0747 and wR = 0.1632 for 4713 observed reflections with I >2(I). The E-stereochemistry of the title compound can be confirmed by the result of the X-ray diffraction analysis.

Redox-responsive carbometalated ruthenium and osmium complexes

Organometallic conjugated complexes have become an important type of stimuli-responsive materials because of their appealing electrochemical properties and rich photonic, electronic, and magnetic properties. They are potentially useful in a wide range of applications such as molecular wires, molecular switches, molecular machines, molecular memory, and optoelectronic detections. This review outlines the recent progress on the molecular design of carbometalated ruthenium and osmium complexes and their applications as redox-responsive materials with visible and near-infrared(NIR) absorptions and electron paramagnetic resonance as readout signals. Three molecule systems are introduced, including the symmetric diruthenium complexes, metal-amine conjugated bi-center system, and multi-center redox-active organometallic compounds. Because of the presence of a metal-carbon bond on each metal component and strong electronic coupling between redox sites, these compounds display multiple reversible redox processes at low potentials and each redox state possesses significantly different physical and chemical properties. Using electrochemical potentials as input signals, these materials show reversible NIR absorption spectral changes, making them potentially useful in NIR electrochromism and information storage.

Bis-triarylamine with a cyclometalated diosmium bridge:A multi-stage redox-active system

A tetra（pyrid-2-yl）-pyrazine-bridged cyclometalated diosmium complex I（PF6）2 with two distal redox- active organic amine suhstituents has been synthesized and characterized. This complex displays four consecutive and separated anodic redox waves at ＋0.24, ＋0.38, ＋0.64, and ＋0.71 V vs. Ag/AgCI. Upon stepwise oxidation, four-step absorption spectral changes in the visible to near-infrared region have been observed. The different redox states of I （1^2＋ through 1^6＋） can be distinguished by the significantly different absorption spectra in the visible and near-infrared region. DFT calculations of 1^3＋ show that the spin is delocalized on both osmium-amine components.

Synthesis and light-emitting properties of 2-(N-phenyl-α-naphthylamino) and 2-dimesitylboron-7-(N-phenyl-α-naphthylamino)-9,9-diethylfluorene

A fluorescent organic triarylamine with a symmetric structure, 2,7-bis(N-α-naphthyl-phenylamino)-9,9- diethylfluorene (NPAEF) was synthesized using two methods, modified Ullmann coupling and modified palladium-catalyzed amination. An activated copper and a combination of Pd(OAc)2/P(t-Bu)3 and Pd(dba)2/P(t-Bu)3 were selected as catalysts to improve yields of reactions. These synthetic procedures were also successfully applied to an asymmetric 2-dimesitylboron-7-(N-phenyl-α-naphthylamino)-9,9-diethylfluorene (BNPEF). Photoluminescent emission peaks in solid film and in diluted solution of NPAEF were both observed at 461 nm, while the main emission peaks of BNPEF appeared at 422 nm in hexane, and at 480 nm in methanol. The double emission peaks of BNPEF in hexane reflected fine structure in the vibrational state. With an increasing polarity of solvent, the main PL emission peaks were red-shifted and vibrational fine structure disappeared. Additionally, energy levels of NPAEF were investigated and an electroluminescence (EL) device of ITO/PVK:NPAEF/Al was fabricated, which showed a turn-on voltage of 9 V and peaked at 462 nm. The EL spectrum was in good agreement with PL spectrum, which indicated that they were from the same emitting center in the device.

Novel organic dye sensitizers containing fluorenyl and biphenyl moieties for solar cells

Three novel triarylamine dyes（AFL1-AFL3） containing fluorenyl and the biphenyl moieties have been designed and synthesized for application in dye-sensitized solar cells.The light-harvesting capabilities and photovoltaic performance of these dyes were investigated systematically through comparison of different π-bridges.The dye with a furan linker exhibited a higher open-circuit voltage（VOC） and monochromatic incident photon-to-current conversion efficiency（IPCE） compared to thiophene and benzene linker.Thus,AFL3 containing a furan linker exhibited the maximum overall conversion efficiency of 5.81%（VOC = 760 mV,JSC = 11.36 mA cm^-2 and ff=0.68） under standard global AM 1.5 G solar condition.

Synthesis, Crystal Structure and Photophysical Properties of a Novel Molecule Containing a Triarylamine and an Oxadiazole Units

N,N-Di-p-tolylaminophenyl)ethenyl]phenyl}-5-(4-bromophenyl)- 1,3,4-oxadiazole (1) containing triarylamine and 2,5-diaryl-1,3,4-oxadiazole units was prepared by Horner-Witting reactions. The structure of the compound was confirmed by 1H NMR, IR, MS and elemental analyses. The crystal structure of 1 was determined by X-ray diffraction analysis. UV absorption spectra and photoluminescent spectra were measured.