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1.
Trans-5,10-bis(1-bromodifluoroacetyl-l-ethoxycarbonyl-methylidene)thianthrene (1b) was prepared from the reaction of BrCF2COC(N2)CO2Et with thianthrene. X-ray single crystal diffraction analysis showed that the intermolecular halogen bonding and hydrogen bonding coexisted in this compound. The bromine atom acted as an electron acceptor in the halogen bond and an electron donor in the hydrogen bond. It is the first example that the bromine atom acted as such a dual role in the hydrogen and halogen bond.  相似文献   

2.
Effects of self-coiling of organic molecules on intramolecular exciplex formation of compound I,in which the carbazole chromophore and terephthalic acid methylester acceptor group are linked by one (CH2)10 chain,and the decrease of the fluorescence intensities of compounds Ⅱ,Ⅲ,and Ⅳ,in which the carbazole chromophore and 3,5-dinitrobenzoate are connected by one aliphatic chain of (CH2)10 (Ⅱ),(CH2)12(Ⅲ),or (CH2)4(Ⅳ),have been studied in the dioxane (DX)-H2O binary system.The results show that self-coiling of organic molecules in DX-H2O facilitates intramolecular exciplex formation of I and induces the decrease of fluorescence intensities of Ⅱ,bacause of the proximity effect brought about by selfcoiling of organic molecules under hydrophobic-lipophilic interaction(HLI) between the excited carbazole chromophore and the acceptor.Since the similar effects are observed even when the concentration of the probes are less than their CAgCs(critical aggregate concentrations )in the DX-H2O mixture with the same φ values,formation of the intermolecular exciplex has been excluded.The effects are found to be strongly depended on φ values,indication that they are mainly driven by HLI.The properties of the acceptors can also affect the intramolecular exciplex formation.With terephthalic acid methylester moiety as the acceptor,the carbazole chromophore exhibits the fluorescence spectra of the exciplex,while with 3,5-dinitrobenzoate moiety as the acceptor,only the fluorescence spectra of excited carbazolyl chromophore are observed.  相似文献   

3.
The new chromophore molecules with nonlinear optical (NLO) properties were prepared by Knoevenagel condensation from 1,8-dimethoxy-4,5-diformyl-9,10-dihydroanthracene and isophorone derivative in the presence of piperidine and acetic acid. In these chromophore, the ring-locked trienes were employed as the conjugation bridge and electron acceptor in D-π-A units. The key intermediate dialdehyde was conveniently prepared via a three step reaction, in which 1,8-dimethoxyanthraquinone was reduced with zinc/acetic acid and sodium/ethanol successively, followed by formylation with 1,1-dichlorodimethyl ether in the presence of TiCI4. The solvatochromism and UV spectra indicate that they have higher second-order nonlinear hyperpolarizability μβ values than the corresponding reference compound, without red shift of the charge transfer band.  相似文献   

4.
A purely organic compound, 4-(9-oxoacridin-10(9 H)-yl) benzonitrile(1), was synthesized and characterized by NMR, UV-Vis, high resolution mass spectrum, and X-ray single-crystal structure analysis. It crystallizes in monoclinic system, space group P21/c with a = 9.7420(2), b = 10.4967(2), c = 14.3896(3) ?, β = 104.755(2)°, V = 1422.94(5), Z = 4, M_r = 296.32, D_c = 1.383 g/cm~3, F(000) = 616, μ = 0.690 mm~(–1), GOOF = 1.035, the final R = 0.0370 and w R = 0.1010 for 2649 observed reflections with I 2σ(I). Compound 1 in tolune exhibits deep blue luminescence with maximum emission peaks at 403 and 419 nm, lifetimes of 3.8 ns and quantum yields of ф = 0.46 at room temperature. The experimental and computational results show that the emission of the compound originates from the acridinone moiety and has π-π* character.  相似文献   

5.
New metal-free organic dye sensitizers containing mono-triphenylamine or bis-triphenylamine as the electron donor, a thiophene as the π-conjugated system, and a cyanoacrylic acid moiety as the electron acceptor were synthesized. The optical and electrochemical properties of the dyes were investigated,and their performance as sensitizers in solar cells was evaluated. Dye-sensitized solar cells based on dye containing bis-triphenylamine as the electron donor produced a photon-to-current conversion efficiency of 6.06%(Jsc = 14.21 m A/cm~2, Voc = 0.62 V, ff = 0.69) under 100 m W/cm~2 simulated AM 1.5 G solar irradiation(100 m W/cm~2).  相似文献   

6.
A new fluorescent probe for lead ions, p-nitrophenyl 3H-phenoxazin-3-one-7-yl phosphoric acid (NPPA), has been synthesized by linking resorufLn (serving as a fluorophore and electron acceptor) to p-nitrophenol (serving as a fluorescence quencher and electron donor) through phosphodiester bonds. When NPPA was irradiated with light, intramolecular fluorescence self-quenching took place due to the PET (photoinduced electron transfer) from the donor to the acceptor. However, upon addition of Pb^Ⅱ, the phosphate ester bonds in the probe were cleaved and the fluorophore was released, accompanying the retrievement of fluorescence.  相似文献   

7.
A series of 1-naphthanilides (1) and 2-naphthanilides (2) with varied substituents at the para- or meta-position of anilino phenyl ring were prepared and their absorption and fluorescence spectra in a nonpolar solvent cyclohexane were investigated. An abnormal long wavelength emission assigned to the charge transfer (CT) state was found for all of the prepared naphthanilides in cyclohexane. A linear free energy correlation between the CT emission energies and the Hammett constants of the substituent was found within series 1 and 2. The value of the linear slope with 1 (0.42 eV) was higher than that with 2 (0.32 eV) being close to that of the substituted benzanilides 3 (0.31 eV) The higher slope value suggested higher charge separation extent in the CT state of 1 than that of 2. It was found that the corresponding linear slope of anilino-substituted benzanilides remained unchanged when para-, meta-, ortho-, or ortho, ortho-methyls were introduced into the anilino moiety, which ruled out the possible contribution of the difference in the steric effect and the electron accepting ability of the naphthoyl acceptor in 1 and 2. Compared with the early reported N-substituted-benzoyl-aminonaphthalene derivatives 4 and 5, it was considered that 1-naphthoyl enhanced the charge transfer in 1 and the proximity of its ^1La and ^1Lb states was suggested to be responsible. It was shown that 1- and/or 2-substituted naphthalene cores acting as either electron acceptor (naphthoyl) or electron donor (aminonaphthalene) were different in not only electron accepting (donating) ability but also shaping the charge transfer pathway.  相似文献   

8.
The title compound △14,15-anhydro-24-thiocarbonylbufalin(1) was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H30O2S·C24H30O2S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845(2), b = 6.8036(3), c = 22.5791(15) , V = 4241.7(4) 3, Mr = 384.21, Z = 4, Dc = 1.204 g/cm3, μ = 1.463 mm-1, F(000) = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed(I 2■(I)). The asymmetric unit contains two independent molecules(I and Ⅱ), which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and Ⅱ are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02(3), permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na+/K+-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group at C-14 play important roles for the inhibition of Na+/K+-ATPase.  相似文献   

9.
SUN  Qiao-Zhen 《结构化学》2011,30(9):1355-1360
A new hexanuclear silver (I) compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in triclinic, space group P with a = 11.611(3), b = 15.610(5), c = 15.624(7) , α = 113.942(6), β = 104.520(6), γ = 104.230(4)°, V = 2304.1(14) 3, C60H77Ag6N22O4.5S6, Mr = 2018.02, Dc = 1.454 g/cm3, μ(MoKα) = 1.435 mm-1, F(000) = 1005, Z = 1, the final R = 0.0468 and wR = 0.1474 for 6608 observed reflections (I > 2σ(I)). In the structure, the S atom of the ligand L2 (L2 = benzaldehyde thiosemicarbazone) served as a triply bridged chelator to connect the six silver atoms into a Ag6L26 cluster. The luminescence property of compound 2 was investigated at room temperature.  相似文献   

10.
A novel zinc complex[ZnL(bipy)(H2O)]×H2O with mixed ligands of 3-hydroxy-2-methylquinoline-4-carboxylic acid(HL)and bipy(bipy=2,2'-bipyridine)was synthesized by solvothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique.The title compound crystallizes in the orthorhombic system of Pbca space group,and exists as an isolated mononuclear complex.The intermolecular hydrogen bonds and strongπ…πstacking interactions form a three-dimensional(3-D)supramolecular network.Solid-state photoluminescence spectrum reveals that it shows an emission in the blue region of the light spectrum.Time-dependent density functional theory(TDDFT)calculations reveal that this emission can be attributed to ligand-to-ligand charge transfer(LLCT).Solid-state diffuse reflectance data show that there is a narrow optical band gap of 1.83 eV.  相似文献   

11.
A novel donor-acceptor(D-A) triphenylamino terpyridine derivative L was facilely synthesized and fully characterized, and its single crystals were obtained and determined by X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.760(5), b =12.516(5), c = 12.850(5) , α = 67.141(5), β = 65.284(5), γ = 75.876(5)o, Mr = 621.54, V = 1575.6(11) 3, Z = 2, Dc = 1.310 g/cm3, μ = 0.245 mm-1, F(000) = 648, the final R = 0.0671 and w R = 0.1869 for 11328 observed reflections with Ⅰ 2σ(Ⅰ). Linear and nonlinear optical properties of terpyridine derivative L were systematically investigated. The maximum two-photon cross-section of L was 382.5 GM(Goeppert-Mayer), measured by two-photon excited fluorescence(TPEF) method. This result demonstrates that the increase of intramolecular charge transfer(ICT) leads to enhanced two-photon absorption(2PA), which could be achieved by introducing additional electron-donor groups to the molecular framework.  相似文献   

12.
<正>New flame-retardant polyimide-silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique.A precursor such as AgNO_3 was used as the source of the silver particles.Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of bis(3-aminophenyl) phenyl phosphine oxide 4 with pyromellitic anhydride 5 in the presence of iso-quinoline as base and in m-cresol solution.The resulting composite film was characterized by FTIR spectroscopy,X-ray diffraction(XRD),transmission electron microscopy(TEM),thermogravimetry(TGA) and differential scanning calorimetry(DSC).The average size of the nanometer Ag particles is about 10 nm.The temperature of 5 and 10%weight loss and also the char yield at 600℃of polyimide-silver nanocomposite 6a were higher than the pure PI 6.  相似文献   

13.
A new hexanuclear silver(I) compound containing thiosemicarbazones with groups of 1-naphthalene was synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analysis and fluorescence spectrum.The title compound crystallizes in monoclinic,space group P2 1 /c with a=16.101(4),b=24.855(7),c=14.492(4),β=109.730(5)°,V=5459(3)3,C 90 H 102 Ag 6 N 24 O 6 S 6,M r=2455.54,D c=1.494 g/cm 3,μ(MoKα)=1.228 mm-1,F(000)=2472,Z=2,the final R=0.0761 and wR=0.1507 for 5258 observed reflections (I > 2σ(I)).In the structure,the S atom of ligand L serves as a triply bridged chelator to connect the six silver atoms into a Ag 6 L 6 cluster.Luminescence investigation reveals that the compound exhibits two ligand-independent cluster-centered electron transfer bands and one ligand-dependent charge transfer band.  相似文献   

14.
The title compound cinobufagin 3-hemisuberate methyl ester(1) was isolated from the venom of Bufo bufo gargarizans CANTOR. The crystal structure of 1, C35H48O9, was determined by single-crystal X-ray diffraction analysis. It belongs to orthorhombic, space group P212121 with a = 8.9338(3), b = 16.2970(4), c = 22.4019(6) , V = 3261.59(16) 3, Mr = 612.73, Z = 4, Dc = 1.248 g/cm3, μ = 0.725 mm-1, F(000) = 1320, S = 1.040, the final R = 0.0374 and wR = 0.0412 for 4458 unique reflections, of which 4088 were observed(I 2σ(I)). In the solid state, short intermolecular C-H...O interactions involving a methine and the ester carbonyl group in cinobufagin moiety and a methyl in the suberate moiety linked adjacent molecules into a three-dimensional network. Detailed analysis of the 1H-NMR data showed that X-ray structure of 1 would be expected to closely resemble the solution conformation in chloroform. Compound 1 was inactive for the inhibition of PC3 and HepG2 cancer cells, but the parent compound cinobufagin showed potent inhibition with IC50 values of 0.145 and 5.48 μM, respectively, indicating that esterification at C(3) decreased the cytotoxic effect of 1.  相似文献   

15.
The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of orthorhombic system(C21H18ClNO4,Mr = 383.81),space group Pca21 with a = 13.913(3),b = 10.273(2),c = 26.488(5),V = 3786.1(13) 3,Z = 8,Dc = 1.347 g/cm3,F(000) = 1600,μ = 0.228 mm-1,the final R = 0.0550 and wR = 0.1278 for 5065 observed reflections(I > 2σ(I)).The title compound in a racemic form was found to exist as a mixture of two enantiomers in an equal ratio in the unit cell.The intermolecular hydrogen bonds link the molecules in a head-to-end manner to generate an infinite chain.  相似文献   

16.
A purely organic D-π-A-π-D type emitter showing thermally activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) was designed and synthesized by utilizing the benzophenone as an acceptor and the N-phenyl-2-napthylamine as a donor moiety.It exhibits considerable TADF character in doped PMMA film and room temperature phosphorescence with a long lifetime of 74 ms at466 nm in solid state.The devices with the configuration of ITO/Mo_2 O_3(4 nm)/mCP(30 nm)/mCP:x wt%NP2 BP/TmTyPB(60 nm)/LiF(1.5 nm)/AI(100 nm) were prepared by vacuum evaporation to explore their electroluminescent performance.Intere stingly,the non-doped device has obtained near-white emission with a fluorescence emission peak at 475 nm and a phosphore scence emission peak at 563 nm having the CIE coordinate of(0.23,0.32) and the maximum external quantum efficiency of 1.09%.  相似文献   

17.
The synthesis, luminescence and electrochemical properties of two novel phenothiazine derivatives were presented, which exhibit good one-photon fluorescence emission. The quantum yields and solvent effects of them were studied in detail. Compound 3,7-bis(2-4'-imidazolylbenzylidenehydrazonoethyl)-(0-ethylphenothiazine) (5) was used as an effective initiator, of which two-photon fluorescence spectra were investigated under 800 nm fs laser pulse and the measured two-photon absorption cross-section was 18 × 10^-50 cm^4·s per photon. Two-photon initiated polymerization microfabrication experiments were carried out. X-ray diffraction analyses revealed that the shape of the compound 3,7-bis(2-pyrid-4'-ylmethylidenehydrazonoethyl)-(0-ethylphenothiazine) (4) looks like a butterfly with nearly planar wings. The dihedral angle of the two benzene rings is 37.6° and there is an obvious π-π stacking interaction between the molecules in the crystal.  相似文献   

18.
Difluoroboron β-diketonate(BF_2 bdk) complexes have attracted much attention due to their outstanding photophysical properties.However,BF_2 bdk with near-infrared fluorescence usually suffer from emission quenching in solid state due to the π-π stacking in aggregation.Herein,we report a BF_2 bdk dye exhibiting donor-acceptor(D-A) structure with the difluoroboron moiety acting as the electron acceptor and the aminonaphthalene as the electron donor.It processes intense molar extinction coefficient,large Stokes shift and strong fluorescence in red/NIR region in both solution and aggregations.It was used for NIR imaging in living cells.  相似文献   

19.
The title compound, methyl 4-(2,4-dichlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate(C_(20) H_(21)Cl_2NO_3, 1) was synthesized and the crystal structure was —determined by single-crystal X-ray diffraction. It crystallizes in tetragonal system, space group P421 c with a = 16.076(3), b = 16.076(3), c = 14.750(2) ?, V = 3811.8(14) ?3, Z = 8, R = 0.0377 and wR = 0.0845. The interactions between compound 1 and bovine serum albumin(BSA) were investigated using fluorescence spectroscopy. The results revealed that compound 1 can effectively quench the intrinsic fluorescence of BSA by static quenching mechanism. The thermodynamic parameters revealed that the action forces between compound 1 and BSA were mainly van der Waals forces and hydrogen bonds. According to F?rster's non-radioactive energy transfer theory, the binding distance between compound 1 and BSA had been determined. Furthermore, the synchronous fluorescence showed that compound 1 has few effects on the microenvironment and conformation of BSA in the binding process.  相似文献   

20.
A new dual fluorescent N,N-dimethylaniline derivative, sodium 4-(N,N-dimethylamino)-benzenesulfonate (SDMAS), is reported. In SDMAS, the electron acceptor is linked to the phenyl ring via a sulfur atom at the para-position of the electron donor. It was found that SDMAS emits dual fluorescence only in highly polar solvent water but not in organic solvents such as formamide, methanol and acetonitrile. In organic solvents only a single-band emission at ca.360 nm was observed in the short wavelength region. The dual fluorescence of SDMAS in water was found at 365 and 475 nm, respectively. Introduction of organic solvent such as ethanol, acetonitrile, and 1,4-dioxane into aqueous solution of SDMAS leads to blue-shift and quenching of the long-wavelength emission. Measurements of steady-state and picosecond time-resolved fluorescence indicate that the long wavelength fluorescence is emitted from a charge transfer (CT) state that is populated from the locally excited (LE) state, with the latter giving off the  相似文献   

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