二萘并噻咯的合成及性能

Siloles constitute an important emerging class of photoluminescent materials. A series of compounds consisting of silole cores and fused naphthalene were synthesized and characterized:6, 6-dimethyl-1, 2, 3, 4, 8, 9, 10, 11-octapropyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-dimethyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, 6, 6-diphenyl-1, 2, 3, 4, 8, 9, 10, 11-octapropyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, and 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-diphenyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole. These dinaphthalene-fused siloles were synthesized from diiodonaphthalene, which was prepared by a direct coupling method. Subsequent reaction in the presence of n-butyllithium yielded 3, 3'-diiodo-2, 2'-binaphthalene. Direct substitution of two chloride ions from Ph₂SiCl₂ or Me₂SiCl₂ with 3, 3'-dilithio-2, 2'-binaphthalene then yielded the multi-substituted silole. Nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry were used to characterize the structures of the siloles. Their optical and electronic properties were investigated using ultraviolet-visible absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry, and density functional theory calculations. The dinaphthalene-fused siloles exhibited similar absorption and emission peaks. Their deep highest occupied molecular orbital level at approximately -5.5 eV indicated that they were chemically stable. Differential scanning calorimetry and thermogravimetric analysis indicated that the siloles were stable up to 309℃. A multilayer electroluminescent device was fabricated using 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-dimethyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole as a light-emitting layer. The resulting device produced bright blue emission, indicating that these siloles may be suitable materials in organic light-emitting devices.     

(E)-(5-(4-(二苯基胺)苯乙烯基)二噻吩并[2,3-b∶3′,2′-d]噻吩基)-2-亚甲基丙二腈的聚集态发光现象的研究

本文报道了对一种电子给体-受体化合物(E)-(5-(4-(二苯基胺)苯乙烯基)二噻吩并[2,3-b∶3′,2′-d]噻吩基)-2-亚甲基丙二腈(TPA-DCST)的合成与光谱学行为的研究。化合物TPA-DCST的分子结构中含有强电子给体(三苯胺)与强电子受体(二氰基乙烯)两个部分,并由二噻吩并[2,3-b∶3′,2′-d]噻吩作为共轭桥将电子给体与受体相连接。在合成方面,采用Wittig反应将三苯胺通过双键与二噻吩并[2,3-b∶3′,2′-d]噻吩相连接、醛基化,并与并二腈经Knoevenagel缩合反应合成目标产物。产物通过了核磁氢谱、碳谱、红外以及高分辨率质谱的确认。光谱方面,主要考察了该化合物的吸收与荧光行为。其最大吸收峰位在412nm左右,归属于π-π*跃迁。在非极性溶剂正己烷中表现出来自分子间聚集而形成的聚集态荧光(550nm),并通过了单分子在CTAB胶束([c]=1.02×10-2 mol/L)的发光(460nm)试验得到验证。溶剂效应表明,该化合物没有出现典型的ICT态的发光现象,其原因在于电子给体与受体相连的共轭桥单元,即二噻吩并[2,3-b∶3′,2′-d]噻吩不具有有效的共轭效应。浓度效应与温度效应进一步表明TPA-DCST分子易于产生分子间聚集态的发光。在THF-H_2O二元溶剂体系中呈现典型的聚集诱导(AIE)发光现象,发光峰位为692nm。随着TPA-DCST分子间的聚集程度的增加,聚集态的荧光出现大范围的红移,直至固体发光红移到710nm。TPA-DCST分子的聚集因素可能来自于疏脂作用、偶极-偶极相互作用等。     

Highly fluorescent oligothiophenes through the incorporation of central dithieno[3,2-b:2',3'-d]pyrrole units

[structures: see text] Dithieno[3,2-b:2',3'-d]pyrrole-based terthiophene (2a-c) and quaterthiophene (3a-c) analogues have been prepared from dithieno[3,2-b:2',3'-d]pyrrole (1) via Stille coupling utilizing a one-pot method. In comparison to the parent oligothiophenes (T(n), where n = 2-4), the resulting dithieno[3,2-b:2',3'-d]pyrrole-based systems exhibit enhanced fluorescence efficiencies in solution (up to 53%). These new oligomeric systems also allow the incorporation of solubilizing side chains without the negative steric interactions that typically reduce backbone planarity.     

Planar beta-linked oligothiophenes based on thieno[3,2-b]thiophene and dithieno[3,2-b:2',3'-d]thiophene fused units

A series of planar beta-linked oligothiophenes based on thieno[3,2-b]thiophene and dithieno[3,2-b:2',3'-d]thiophene fused units were synthesized. The optical data indicate a blue shift of the absorption maximum in comparison to the alpha-linked analogues due to cross-conjugation between fused rings. The crystal structures of 3,3'-bi(thieno[3,2-b]thiophene) and 3,3';6',3"-ter(thieno-[3,2-b]thiophene) reveal edge-to-face pi-stacked dimer motifs, whereas the crystal structure of 3,3'-bis(dithieno[3,2-b:2',3'-d]thiophene) consists of face-to-face pi-stacked molecules. [structure: see text]     

Linear fused dithieno[2,3-b:3'2'-d]thiophene diimides

Linear fused dithieno[2,3-b:3'2'-d]thiophene diimides (DTTDIs, 1-4) were synthesized. Physicochemical investigations suggested that these diimides might be used as potential n-channel organic semiconductors. Single-crystal analysis of N-propyl DTTDI (1) revealed that molecules adopt a layered herringbone packing motif.     

Reduced band gap dithieno[3,2-b:2',3'-d]pyrroles: new n-type organic materials via unexpected reactivity

Direct addition of tetracyanoethylene to N-(p-hexylphenyl)dithieno[3,2-b:2',3'-d]pyrrole yields not only the aromatic mono- and bis-tricyanovinyl-substituted products but also a quinoidal product with dicyanomethylene groups. The analogous reaction with dithieno[3,2-b:2',3'-d]thiophene yields exclusively the aromatic mono-tricyanovinyl product. The aromatic and quinoidal products possess red-shifted absorptions, increased electron affinities, and favorable pi-stacking motifs in comparison to the unsubstituted oligomers.     

From model compounds to extended pi-conjugated systems: synthesis and properties of dithieno[3,2-b:2',3'-d]phospholes

To explore their suitability for applications in molecular optoelectronics and as sensory materials, novel dithieno[3,2-b:2',3'-d]phospholes have been synthesized and their reactivity and properties investigated. An efficient two-step synthesis allowed for a modular assembly of differently functionalized compounds. The dithieno[3,2-b:2',3'-d]phosphole system exhibits extraordinary optoelectronic properties with respect to wavelength, intensity, and tunability. Owing to the nucleophilic nature of the central phosphorus atom, its significant electronic influence on the conjugated pi system can be altered selectively by chemically facile modifications such as oxidation or complexation with Lewis acids or transition metals. All the dithienophosphole species presented show very strong blue photoluminescence with excellent quantum yield efficiencies supporting their potential utility as blue-light emitting components in organic light emitting diodes (OLEDs). Furthermore, depending on the electronic nature of the phosphorus center, the materials exhibit distinctive optoelectronic properties suggesting that the dithieno[3,2-b:2',3'-d]phosphole system may be useful as sensory material. Theoretical calculations, including time-dependent DFT methods, revealed the excellent predictability of the structures and optoelectronic properties of the functionalized dithienophospholes allowing the design of future dithieno[3,2-b:2',3'-d]phosphole-based materials to be "stream-lined". By using tin-functionalized dithienophosphole monomers, a strategy, which involves Stille coupling, towards extended pi-conjugated materials with significantly redshifted optoelectronic properties is also presented.     

Bis[bis-(4-alkoxyphenyl)amino] derivatives of dithienylethene, bithiophene, dithienothiophene and dithienopyrrole: palladium-catalysed synthesis and highly delocalised radical cations

Five diamines with thiophene-based bridges--(E)-1,2-bis{5-[bis(4-butoxyphenyl)amino]-2-thienyl}ethylene (1), 5,5'-bis[bis(4-methoxyphenyl)amino]-2,2'-bithiophene (2), 2,6-bis[bis(4-butoxyphenyl)amino]dithieno[3,2-b:2',3'-d]thiophene (3), N-(4-tert-butylphenyl)-2,6-bis[bis(4-methoxyphenyl)amino]dithieno[3,2-b:2',3'-d]pyrrole (4 a) and N-tert-butyl-2,6-bis[bis(4-methoxyphenyl)amino]dithieno[3,2-b:2',3'-d]pyrrole (4 b)--have been synthesised. The syntheses make use of the palladium(0)-catalysed coupling of brominated thiophene species with diarylamines, in some cases accelerated by microwave irradiation. The molecules all undergo facile oxidation, 4 b being the most readily oxidised at about -0.4 V versus ferrocenium/ferrocene, and solutions of the corresponding radical cations were generated by addition of tris(4-bromophenyl)aminium hexachloroantimonate to the neutral species. The near-IR spectra of the radical cations show absorptions characteristic of symmetrical delocalised species (that is, class III mixed-valence species); analysis of these absorptions in the framework of Hush theory indicates strong coupling between the two amine redox centres, stronger than that observed in species with phenylene-based bridging groups of comparable length. The strong coupling can be attributed to high-lying orbitals of the thiophene-based bridging units. ESR spectroscopy indicates that the coupling constant to the amino nitrogen atoms is somewhat reduced relative to that in a stilbene-bridged analogue. The neutral species and the corresponding radical cations have been studied with the aid of density functional theory and time-dependent density functional theory. The DFT-calculated ESR parameters are in good agreement with experiment, while calculated spin densities suggest increased bridge character to the oxidation in these species relative to that in comparable species with phenylene-based bridges.     

Synthesis of dithieno[2,3-b:3',2'-d]thiophenes-building blocks for cross-conjugated beta-oligothiophenes

Syntheses of annelated and functionalized beta-trithiophenes (dithieno[2,3-b:3',2'-d]thiophenes), building blocks for the helically annelated, cross-conjugated beta-oligothiophenes, are reported. UV-vis spectra reveal that the effect of octyl substituents on the onset of electronic absorption in annelated beta-trithiophenes is negligible compared to the effect of helical distortion in the higher beta-oligothiophenes.     

Solution and solid-state properties of highly fluorescent dithieno[3,2-b:2',3'-d]pyrrole-based oligothiophenes

Dithieno[3,2-b:2',3'-d]pyrrole-based terthiophene and quaterthiophene analogues have been prepared from N-functionalized dithieno[3,2-b:2',3'-d]pyrroles (DTPs) via Stille coupling. In order to thoroughly study the structure-function property relationships within these DTP-based oligothiophenes, an oligomer series was prepared that allows for the investigation of a number of structural effects including chain length, thiophene functionalization, and pyrrole N-functionalization. As pyrrole N-functionalization allows the incorporation of solubilizing side chains without the unwanted steric interactions that typically reduce backbone planarity, the effect of the bulk of these side chains on the optical properties in both solution and the solid state has been carefully investigated. The DTP-based quaterthiophene, N-tert-butyl-2,6-bis(2'-thienyl)dithieno[3,2-b:2',3'-d]pyrrole was characterized via X-ray crystallography and was found to crystallize in the monoclinic space group P2(1)/c with a = 17.489(4) ?, b = 7.8855(16) ?, c = 14.540(3) ?, β = 108.37(3)°, and Z = 4. The effect of side chains on the solid-state packing of the DTP-based quaterthiophenes was further investigated through X-ray diffraction of solution processed thin films. In comparison to the parent oligothiophenes, the resulting DTP-based systems exhibit enhanced fluorescence efficiencies in solution (up to 66%) and measurable solid-state emission from thin films.     

A simple and efficient route to N-functionalized dithieno[3,2-b:2',3'-d]pyrroles: fused-ring building blocks for new conjugated polymeric systems

A general synthetic route has been developed for the simple and efficient preparation of N-functionalized dithieno[3,2-b:2',3'-d]pyrroles. These synthetic methods utilize N-functionalized N-(3'-thienyl)-3-aminothiophenes produced from the Pd-catalyzed amination of 3-bromothiophene with primary amines, followed by a one-pot bromination/cyclization process. This combination allows the convenient preparation of a variety of N-functionalized dithieno[3,2-b:2',3'-d]pyrroles (where substituent = hexyl, octyl, decyl, tert-butyl, and p-hexylphenyl) in good yield (65-82%). Characterization of the structure and reactivity of this class of compounds is also described, including electrochemical and photophysical data for all compounds and X-ray structural data for the octyl-, tert-butyl-, and p-hexylphenyl-functionalized compounds.     

Photochromic oligothienoacene derivatives with photo-switchable luminescence properties and computational studies

Photochromic thieno[3,2-b]thiophenes and dithieno[3,2-b:2',3'-d]thiophene with photo-switchable luminescence properties have been synthesized using a Suzuki cross-coupling reaction; their electronic structures, and photochromic and luminescence behaviour have also been studied.     

Molecular tuning in highly fluorescent dithieno[3,2-b:2',3'-d]pyrrole-based oligomers: effects of N-functionalization and terminal aryl unit

A series of eight conjugated oligomers consisting of central dithieno[3,2-b:2',3'-d]pyrroles (DTPs) end-capped with either thienyl or phenyl groups have been prepared from N-alkyl-, N-aryl-, and N-acyl-dithieno[3,2-b:2',3'-d]pyrroles via Stille and Suzuki cross-coupling. The DTP-based quaterthiophene, N-phenyl-2,6-bis(2-thienyl)dithieno-[3,2-b:2',3'-d]pyrrole was characterized via X-ray crystallography and was found to crystallize in the orthorhombic space group Pna2(1) with a = 10.8666(3) ?, b = 22.8858(6) ?, c = 7.4246(2) ?, and Z = 4. The full oligomeric series was thoroughly investigated via photophysical, electrochemical, and DFT calculations in order to correlate the cumulative effects of both aryl end-groups and N-functionalization on the resulting optical and electronic properties. Through such molecular tuning, it was found to be possible to modulate the HOMO energy by as much as 0.32 V and to generate highly fluorescent oligomers with solution fluorescence efficiencies as high as 92%.     

Dithienothiophene (DTT)-based dyes for dye-sensitized solar cells: synthesis of 2,6-dibromo-DTT

A one-pot synthesis of 2,6-dibromodithieno[3,2-b;2',3'-d]thiophene (dibromo-DTT, 4) was developed. A key step was bromodecarboxylation of DTT-2,6-dicarboxylic acid, obtained by saponification of the diester 1. The donor-acceptor dye DAHTDTT (13), based on a central 2,6-bis[2'-(3'-hexylthienyl)]dithieno[3,2-b;2',3'-d]thiophene core (9), was prepared and incorporated in a dye-sensitized solar cell (DSC), which exhibited an energy conversion efficiency of 7.3% with V(oc) of 697 mV, J(sc) of 14.4 mA/cm(2), and ff of 0.73 at 1 sun.     

Improved synthesis of dithieno[3,2-b:2',3'-d]thiophene (DTT) and derivatives for cross coupling

An improved synthesis of dithieno[3,2-b:2',3'-d]thiophene (DTT) and its 2,6- and 3,5-dibromo derivatives has been devised; Stille cross coupling of 2,5-(bistrimethylstannyl)-DTT afforded the oligomer 12.     

Synthesis of new condensed derivatives of pyrano[4,3-<Emphasis Type="Italic">b</Emphasis>]thieno[3,2-<Emphasis Type="Italic">e</Emphasis>]pyridine and pyrido[3',2':4,5]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

The reactions of 2-methyl (propyl) substituted 8,8-dimethyl-7,10-dihydro-4H,8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]oxazines with primary amines give 2-methyl (propyl) substituted 8,8-di- methyl-7,10-dihydro-8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]pyrimidin-4(3H)-ones or 3-acetyl-N-alkyl- and N-alkyl-3-butyrylamino-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]- pyridine-2-carboxamides depending on steric hindrance in the amines.     

Luminescent digold ethynyl thienothiophene and dithienothiophene complexes; their synthesis and structural characterisation

A series of protected and terminal dialkynes with extended pi-conjugation through the fused oligothienyl linker unit in the backbone, 2,5-bis(trimethylsilylethynyl)thieno[3,2-b]thiophene 1a, 5,5'-bis(trimethylsilylethynyl)dithieno[3,2-b:2',3'-d]thiophene 1b, 2,5-bis(ethynyl)thieno[3,2-b]thiophene 2a, 5,5'-bis(ethynyl)dithieno[3,2-b:2',3'-d]thiophene 2b, has been synthesized and characterised. The digold alkynyl complexes [(Ph3P)Au(C[triple bond]C)(C6H2S2)(C[triple bond]C)Au(PPh3)] 3a and [(Ph3P)Au(C[triple bond]C)(C8H2S3)(C[triple bond]C)Au(PPh3)] 3b have then been prepared by the reaction of two equivalents of Ph3PAuCl and a methanolic KOH solution of 1a and 1b, respectively. The complexes have been characterised spectroscopically. The crystal structures show that the gold centres adopt a linear two-coordinate geometry appropriate for Au(i) complexes. Within the crystals adjacent molecules are linked by Au...S intermolecular interactions in the range 3.48-3.89 A, but there are no short Au...Au contacts. The absence of Au...Au interactions in solution is confirmed by UV/visible absorption and emission spectroscopy, the spectra being dominated by ligand-centred pi-pi* interactions.     

Solid-state supramolecular organization, established directly from powder diffraction data, and photoluminescence efficiency of rigid-core oligothiophene-S,S-dioxides

The "rigid-core" material 3,5-dimethyl-2,3'-bis(3-methylthiophene)-dithieno[3,2-b:',3'-d]thiophene-4,4-dioxide (DTTOMe4) has the highest photoluminescence ever reported for thiophene-based molecules in the solid state. We report the structure of this material, determined directly from powder X-ray diffraction data using the Genetic Algorithm method for structure solution, followed by Rietveld refinement, and the structural properties are discussed in relation to the structures of the corresponding subsystems DTTO and DTTOMe. While the crystal structures of the latter compounds contain cofacial dimers, the crystal structure of DTTOMe4 comprises layers of molecules aligned in an antiparallel fashion. Intermediate neglect of differential overlap with single configuration interaction (INDO/SCI) calculations on the intermolecular interactions in the three crystal structures show that the different solid-state photoluminescence efficiencies of DTTOMe4, DTTOMe, and DTTO cannot be correlated with the different types of dipole-dipole alignment in the solid state. Instead, photoluminescence efficiencies correlate well with the rate of formation of nonradiatively decaying charge-transfer pairs upon photoexcitation. Because of larger intermolecular distances in DTTOMe4, the photoluminescence is less effectively quenched by charge-transfer processes than in DTTOMe and DTTO.     

Quantitation of mutagenic/carcinogenic heterocyclic aromatic amines in food products.

A method for screening genotoxic heterocyclic aromatic amines in cooked foods using solid-phase extraction and high-performance liquid chromatography with ultraviolet and fluorescence detection is described. Solid-phase extraction includes basic extraction on diatomaceous earth (Extrelut) and subsequent purification on propylsulphonic acid silica gel. This convenient procedure separates the analytes into a polar group and an apolar group. We have identified the following components in the two groups. The polar group contains aminoimidazoazaarenes i.e. 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, and glutamic acid pyrolysates, i.e. 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2-aminodipyrido[1,2-a:3',2'-d]-imidazole. The apolar group consists of five carbolines: 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, 2-amino-9H-pyrido[2,3-b]indole, 9H-pyrido[3,4-b]indole and 1-methyl-9H-pyrido[3,4-b]indole. The extraction efficiencies range from 45 to 90%, and the detection limits are in the low nanogram per gram range. The method was applied to the analysis of heterocyclic aromatic amines in pan-fried, oven-cooked and barbecued salmon.     

New approaches to the synthesis of functionally substituted pyrido[3′,2′:4,5]thieno[3,2-b]pyridines and the structure of the products obtained

Substituted pyrido,[3',2':4,5]thieno[3,2-b]pyndines were obtained by the reaction of 3-amino-2-benzoylthieno [2,3-b]pyridines with malononitrile and the reaction of 3-cyanopyridine-2(IH)-thiones with 2-aryl-3-bromo-I,I-dicyanopropene. 2-Amino-4-(4-bromophenyl)-7, 9-dimethyl-3-cyanopyrido [3',2':4,5]thieno[3, 2-b]-pyridine was used for the synthesis of a derivative of pyrido[3",2":4', 5']thieno[2',3':5,6]pyrido[2,3-d]-pyrimidine. The structure of these compounds was confirmed by spectral data and x-ray diffraction structural analysis.Deceased.