Synthesis,X-ray crystal structure and optical properties of novel 2,5-diaryl-1,3,4-oxadiazole derivatives containing substituted pyrazolo[1,5-a]pyridine units

A series of pyrazolo[1,5-a]pyridine-containing 2,5-diaryl-1,3,4-oxadiazole derivatives were synthesized and their structures were characterized by IR, ¹H NMR and HRMS spectra. The crystal structure of 3a was determined using single crystal X-ray crystallography. Its spatial structure was found to be monoclinic, and all aromatic rings were approximately coplanar, which allowed conjugation. The absorption results showed that compounds 1a–f presented their absorption peaks ranging from 264 nm to 290 nm, while compounds 3a–f with a larger conjugation system exhibited red-shifted absorption character (absorption maxima between 283 nm and 303 nm) compared to the corresponding absorption of 1a–f. Fluorescence spectra revealed that these compounds exhibited blue fluorescence (421–444 nm) in dilute solutions and showed quantum yields of fluorescence between 0.32 and 0.83 in dichloromethane.     

Synthesis, X-ray crystal structure and optical properties of novel 2,5-diaryl-1,3,4-oxadiazole derivatives containing substituted pyrazolo[1,5-a]pyridine units

A series of pyrazolo[1,5-a]pyridine-containing 2,5-diaryl-1,3,4-oxadiazole derivatives were synthesized and their structures were characterized by IR, ¹H NMR and HRMS spectra. The crystal structure of 3a was determined using single crystal X-ray crystallography. Its spatial structure was found to be monoclinic, and all aromatic rings were approximately coplanar, which allowed conjugation. The absorption results showed that compounds 1a-f presented their absorption peaks ranging from 264 nm to 290 nm, while compounds 3a-f with a larger conjugation system exhibited red-shifted absorption character (absorption maxima between 283 nm and 303 nm) compared to the corresponding absorption of 1a-f. Fluorescence spectra revealed that these compounds exhibited blue fluorescence (421-444 nm) in dilute solutions and showed quantum yields of fluorescence between 0.32 and 0.83 in dichloromethane.     

Synthesis and anti-inflammatory activity of some novel 1,3,4-oxadiazole derivatives

Some novel 1,3,4-oxadiazoline and 1,3,4-oxadiazole derivatives have been synthesized from 3-hydroxy-5,6-diphenyl-1,2,4-triazine. Illucidation of the structures of the isolated products has been proved in the light of their elemental analysis, spectroscopic data and unambiguous synthesis in certain cases. Some derivatives have shown promising anti-inflammatory activity in comparison to phenylbutazone.     

The synthesis,crystal structure and photophysical properties of three novel naphthalimide dyes

Three new naphthalimide derivatives containing an electron-donor moiety (carbazole), 4-carbazolyl-N-methyl-1,8-naphthalimide, 4-carbazolyl-N-cyclohexyl-1,8-naphthalimide and 4-carbazolyl-N-phenyl-1,8-naphthalimide were synthesized and crystal structures confirmed. Crystallographic data revealed that the interplanar angles (θ) of the carbazole and naphthalimide moieties were, respectively, 70.7° and 66.5°. The UV–vis absorption and photoluminescent spectra of the systems in n-hexane, CHCl₃, tetrahydrofuran and CH₂Cl₂ were investigated. The lowest absorption band of the naphthalimide molecular centered at 400–420 nm was assigned to charge-transfer transition with emission at ≈440 nm in n-hexane and at ≈560 nm in CH₂Cl₂.     

Hydrothermal synthesis,crystal structure and optical properties of a 2-D heterometallic iodoplumbate

A novel two-dimensional heterometallic iodoplumbate, [Pb₃I₁₀Cu₄(phen)₂]_n (phen = 1,10-phenanthroline) constructed from [Pb₃I₁₀]^4? iodoplumbate chains and [Cu₂I₄(phen)]^2? entities has been hydrothermally synthesized and structurally characterized. The solid compound exhibits an intriguing semiconducting property with E_g = 2.62 eV. The thermochromic behavior of the compound has been also studied.     

新型杂环Schiff碱的合成、晶体结构及荧光性质研究

以3-甲基-2-噻吩甲醛和4-氨基安替比林为原料合成了一种新的schiff碱--1,5-二甲基-4-[(3-甲基噻吩-2-亚甲基)氨基]-2-苯基-1,2-二氢吡唑-3-酮,采用IR、元素分析法、NMR及X-射线单晶衍射法对其结构进行了表征.该化合物属于正交晶系,P212121空间群,晶胞参数a=0.697 81(6)...     

Preparation and properties of polyphenylene-1,3,4-oxadiazole fibres

Copolymers of terephthalic and isophthalic acid (CPODZ) in 1:1 and 3:1 molar ratios with hydrazine sulphate and concentrated sulphuric acid were wet spun using water and H₂SO₄ coagulation baths. The filaments spun into water bath have inferior mechanical properties than those spun in H₂SO₄ bath. Physical properties, namely tenacity, elongation, modulus, resilience, elastic recovery, and dynamic mechanical properties were investigated. 1:1 CPODZ filaments showed higher strength, modulus and elasticity than 1:3 CPODZ filaments. These CPODZ fibres had a higher dynaic modulus and low loss tangent. The density and moisture regain of CPODZ filaments were also determined. The density of 1:1 CPODZ filaments was higher. The filaments spun in water bath had higher moisture regain. 1:1 CPODZ filaments had less regain compared to 1:3 CPODZ filaments.     

Synthesis of 2-hetaryl-5-phenyl-1,3,4-oxadiazole and bis-1,3,4-oxadiazole derivatives and their use as fluorescent whiteners for polyester fibres

Heterocyclic carboxylic acids (1) and benzoyl hydrazide (2) were condensed in the presence of polyphosphoric acid to give yellow to colourless compounds (3) which could be applied on polyester fibres as fluorescent whiteners. The dihydrazides (4) were condensed with aromatic acids (5) in the presence of polyphosphoric acid to yield bis-1,3,4-oxadiazole derivatives (6). These could also be used as fluorescent whiteners for polyester fibres. The spectroscopic properties in relation to the structural features of the compounds are discussed.     

Electrochemical synthesis,characterization and capacitive properties of novel thiophene based conjugated polymer

In this paper, a novel thiophene based monomer, 1-(pyren-1-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole, PThP, was synthesized and characterized by ¹H NMR and ¹³C NMR spectroscopic methods. The electrochemical behavior and electropolymerization of this novel monomer were performed on pencil graphite electrode (PGE) by cyclic voltammetry. The effect of solvent, dopant, scan number and scan rate on the electropolymerization and properties of the conjugated polymer films were investigated. The capacitive properties of the poly(PThP) films were tested by electrochemical impedance spectroscopy (EIS). The highest specific capacitance value was calculated for the conjugated polymer modified PGE that was obtained in 0.1 M tetrabutylammonium perchlorate/dichloromethane solution for 30 cycles at 25 mV/s scan rate as 25.45 mF cm⁻². The surface morphologies of the conjugated polymer modified electrodes were determined by scanning electron microscopy (SEM).     

Hydrothermal synthesis,crystal structure and spectroscopic properties of a novel 3D chromium(III) complex

The hydrothermal synthesis of CrCl₃·6H₂O, NaOH, 2,6-dipicolinic acid (H₂dpa), salicylic acid (HSAL) in water and ethanol at 140 °C for 5 days yields a novel 3D coordination polymer NaCr(C₇H₃O₄N)₂(H₂O)₂ (1). In the complex, each Cr center is in a distorted octahedral environment, and coordinates to two nearly perpendicular dpa anions, which act as tridentate ligands. Na(I) is in a compact sixfold coordination with three non-coordination carbonyl oxygen atoms of neighboring asymmetric units, a carboxylate oxygen atom shares coordination with Cr(III) and two aqueous. Two adjacent asymmetric units are linked together through Na–O and a set of intermolecular hydrogen bonds, which generates the finally 3D supermolecular network structure.     

1,4-二[2-(吡啶基)-1,3,4-(噁)二唑基]苯的合成及其光谱性质

利用双二酰肼的脱水化反应制备了两种新颖对称双二噁唑。通过IR、1HNMR、MS及元素分析等对化合物的结构进行表征。研究了此双噁二唑化合物在溶剂DMF中浓度为1×10-7mol/L时的紫外光谱和荧光光谱性质。结果表明:目标化合物在DMF溶液的最大紫外吸收波长在310 nm,最大荧光发射波长在364和383 nm。     

芴酮-芳香醛-双腙的合成、晶体结构及光限幅性能

合成了4种新的标题化合物,通过红外光谱、核磁共振、质谱及元素分析对它们结构进行了表征,并通过单晶X射线衍射确定了芴酮-N,N-二甲基苯甲醛-双腙的结构,结果表明该晶体为正交晶系,属Pbca空间群,具有较大的共轭体系和良好的平面性.采用Z-扫描技术测试了4种化合物的光限幅性能,研究表明其中3种化合物对532 nm激光有良好的光限幅性能,其双光子吸收截面分别为3.19×10-46、3.96×10-46和4.31×10-46 cm4*s/photon.     

Optical limiting materials: Synthesis,electrochemical and optical studies of new thiophene based conjugated polymers carrying 1,3,4‐oxadiazole units

In this communication we report synthesis of three new donor‐acceptor (D–A) type conjugated polymers carrying 1,3,4‐oxadiazole moiety and thiophene unit with different side groups at its 3,4 positions (4‐methoxybenzyl:P1, 3‐methylbenzyl:P2 and 4‐nitrobenzyl:P3) through polycondensation route using a series of newly synthesized monomers. The structures of new monomers and polymers were confirmed by NMR, FTIR spectroscopic methods followed by elemental analysis. Further, molecular weight and thermal stability were determined using gel permeation chromatography and thermogravimetric analysis. The linear optical and electrochemical properties of polymers were investigated by UV–vis absorption, fluorescence spectroscopic, and cyclic voltammetric studies. The polymers P1–P3 were found to be thermally stable and their electrochemical band gaps were determined to be 1.98, 2.14, and 2.18 eV respectively. Further their nonlinear optical properties were investigated by Z‐scan method using 532 nm, 7 ns laser pulses. The results reveal that they possess good optical limiting behavior due to effective three‐photon absorption (3PA) with absorption coefficient 2.5 × 10^?24 m^?3W², 1.6 × 10^?24 m^?3W², and 1.0 × 10^?24 m^?3W². POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

The synthesis,photophysical and electrochemical properties of a series of novel 3,8,13-substituted triindole derivatives

The synthesis and properties of a series of new 3,8,13-substituted triindole derivatives 1a–1e are reported. The 3,8,13-substituted triindoles were thermally robust with high decomposition temperatures (≥405 °C) and high melt transitions (219 °C–373 °C). Compound 5e was crystallized in the monoclinic system with the space group P2₁/n. These compounds showed UV–Vis absorption (λ_max^Abs) in the range of 311–345 nm in DCM solution and 371–391 nm in solid state, and fluorescence maxima (λ_max^Em) in the range of 394–412 nm in DCM solution and 416–461 nm in solid state. The fluorescence quantum yields ranged from 0.27 to 0.58. The estimated electron affinities (LUMO levels) and estimated ionization potential (HOMO levels) of compounds 1a–1e are 3.54–3.71 eV and 5.12–5.48 eV, respectively. Quantum chemical calculations using DFT B3LYP/6-31G showed nearly identical LUMO (−0.72 to −1.10 eV) and HOMO (−4.65 to −4.84 eV) values. These results demonstrated that the new 3,8,13-substituted triindoles are promising thermally stable host materials for organic light-emitting diodes with reasonable hole mobility.     

1,3,4-噁二唑取代芳酰基硫脲的合成及杀菌活性研究

设计合成了10个1,3,4-噁二唑取代的芳酰基硫脲类化合物,所有化合物的结构经IR,^1HNMR及元素分析确证。初步生物测试结果表明,大多数化合物具有较好的杀菌活性。     

The synthesis, crystal structures and photophysical properties of a series of novel 4,6-diphenyl-1,9-anthrazolines

The synthesis and properties of a series of nine new 4,6-diphenyl-1,9-anthrazolines molecules 1a-1i are reported. Compounds 1a-1i were synthesized by Friedländer condensation of 4,6-dibenzoyl-1,3-phenylenediamines and acetyl-functionalized compounds in the presence of polyphosphoric acid as catalyst, in yields ranging from 60% to 94%. The 4,6-diphenyl-1,9-anthrazolines are thermally robust with high decomposition temperatures (>371.0 °C) and high melt transitions (215.1-322.8 °C). Compounds 1a and 1f crystallized in the triclinic system with the space groups P-1. All of them show the lowest energy absorption bands (λ_max^Abs: 397-454 nm), revealing low optical band gaps (2.55-3.00 eV). The compounds emit blue fluorescence with λ_max^Em ranging from 432 to 493 nm in dilute toluene solution. 4,6-Diphenyl-1,9-anthrazolines 1a-1i have a formal reduction potential in the range −1.02 to −1.19 V (versus SCE) and estimated electron affinities (LUMO levels) of 3.21-3.38 eV. These results demonstrate that the new 4,6-diphenyl-1,9-anthrazolines are promising thermally stable n-type semiconductors for organic electronics.     

The synthesis and optical properties of novel fluorescent iminocoumarins and bis-iminocoumarins: Investigations in the series of urea derivatives

The condensation of 3-cyano-7-diethylamino-iminocoumarin with various isocyanates and diisocyanates as C-electrophiles gave a new series of N-substituted iminocoumarins and bis-iminocoumarins. The ten compounds obtained were characterized using IR, ¹H NMR, ¹³C NMR, elemental analysis and mass spectrometry. Their optical properties, studied in dichloromethane by UV/vis absorption and fluorescence spectroscopy, were found to depend strongly upon the nature of the substituent borne by the imino group. For the sake of comparison, the optical properties of selected compounds were also analyzed in ethanol. Of the iminocoumarins studied, the alkylurea derivatives displayed the most interesting spectroscopic characteristics and may be of potential use as novel fluorescent probes in media of various polarity.     

The synthesis and two-photon excited fluorescence properties of novel branched fluorene derivatives

Two novel, V-shaped fluorene derivatives branched from triphenylamine and their linear analogue were synthesized via Cu-mediated Ullmann condensation and subsequent Pd-catalyzed Heck coupling reaction. Their two-photon excited fluorescence properties as well as their linear absorption and single-photon excited fluorescence properties were examined. When excited at 730 nm by a Ti:sapphire femtosecond laser, the compounds exhibited strong two-photon excited blue fluorescence. The two-photon excited fluorescence cross-sections of V-shaped derivatives in toluene at 730 nm were 506 GM in the case of N, N-bis{7-[4′-(N, N-diphenylamino)styryl]-9,9-diethyl-9H-fluorene-2-yl}-aniline) and 397 GM for N, N-Bis{7-[4′-(N, N-diphenylamino)styryl]-9,9-diethyl-9H-fluorene-2-yl}-4-acetyl-aniline), respectively.     

The synthesis and two-photon excited fluorescence properties of novel branched fluorene derivatives

Two novel, V-shaped fluorene derivatives branched from triphenylamine and their linear analogue were synthesized via Cu-mediated Ullmann condensation and subsequent Pd-catalyzed Heck coupling reaction. Their two-photon excited fluorescence properties as well as their linear absorption and single-photon excited fluorescence properties were examined. When excited at 730 nm by a Ti:sapphire femtosecond laser, the compounds exhibited strong two-photon excited blue fluorescence. The two-photon excited fluorescence cross-sections of V-shaped derivatives in toluene at 730 nm were ∼506 GM in the case of N, N-bis{7-[4′-(N, N-diphenylamino)styryl]-9,9-diethyl-9H-fluorene-2-yl}-aniline) and 397 GM for N, N-Bis{7-[4′-(N, N-diphenylamino)styryl]-9,9-diethyl-9H-fluorene-2-yl}-4-acetyl-aniline), respectively.     

Co-doped willemite ceramic pigments: Technological behaviour,crystal structure and optical properties

Cobalt-doped willemite is a promising blue ceramic pigment, but some important aspects concerning crystal structure, optical properties and technological behaviour are still undisclosed. In order to get new insight on these features, willemite pigments (Zn_2?xCo_xSiO₄, 0 < x < 0.3) were synthesized by the ceramic route and characterized from the structural (XRPD with Rietveld refinement), optical (DRS and colorimetry), microstructural (SEM, STEM, TEM, EDX, EELS) and technological (simulation of the ceramic process) viewpoints. The incorporation of cobalt in the willemite lattice, taking preferentially place in the Zn1 tetrahedral site, induces an increase of unit-cell parameters, metal–oxygen distances, and inter-tetrahedral tilting. It causes shifting and enhanced splitting of spin-allowed bands of Co²⁺ in tetrahedral coordination, implying slight changes of crystal field strength Dq and Racah B parameter, but increasing spin-orbit coupling parameter λ. Willemite pigments impart deep blue hue to ceramic glazes and glassy coatings with a colouring performance better than commercial Co-bearing colorants in the 800–1200 °C range. Detailed SEM-TEM investigation and microanalysis proved that no diffusion phenomena occur at the pigment–glassy coating interface and that willemite pigments are chemically inert during firing at 1050 °C.