A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synth...A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synthesized by Heck coupling reaction and characterized with UV-vis, Fourier transform infrared （ FT-IR ）, ^1H-NMR and photoluminescence （ PL ） spectroscopy, oxa-MEHPV possesses an outstanding thermal stability and shows excellent solubility in common organic solvents such as dichloromethane, chloroform, toluene, and tetrahydrofuran（THF）. The introduction of the electron-deficient 1, 3, 4-oxadiazole units into the MEH-PPV backbone also increases the electron affinities of the conjugated segment, which leads to the blue-shift of the maximum absorption wavelength and makes the polymer have a high optical band-gap energy, good electron-transporting stability and high PL quantum yield.展开更多
1、2－O－Isopropylidene－3－C－cyano－5－O－benzoyl－α－D－xylose 2 was preparedstereoselectively from 1，2－O－isopropylidene－3－oxo－5－O－benzoyl－α－D－xylose 1．The structure of 2was studied by two－dimensiona...1、2－O－Isopropylidene－3－C－cyano－5－O－benzoyl－α－D－xylose 2 was preparedstereoselectively from 1，2－O－isopropylidene－3－oxo－5－O－benzoyl－α－D－xylose 1．The structure of 2was studied by two－dimensional NMR spectroscopy in conjunction with X－ray crystallography of itscorresponding 5－phenyl－1，2，4－oxadiazole isocarbonucleoside derivative 3． The absoluteconfigurations of 2 and 3，and conformation of 3 are described herein．展开更多
A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesizedand characterized. Its UV and photoluminescent properties were studied. The strong UVabsorption intensity around 462 nm attributed t...A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesizedand characterized. Its UV and photoluminescent properties were studied. The strong UVabsorption intensity around 462 nm attributed to spin-forbidden triplet metal–ligand charge transferband and photoluminescence at 518 nm were observed. This indicated that achieved iridiumcomplex could be used as an efficient electrophosphorescent material.展开更多
A novel compound,2-（anthracen-9-yl）-5-p-tolyl-1,3,4-oxadiazole（C23H16N2O）,has been synthesized by the condensation of 4-methylbenzohydrazide and anthracene-9-carbaldehyde in an ethanol solution with chloramine-T.T...A novel compound,2-（anthracen-9-yl）-5-p-tolyl-1,3,4-oxadiazole（C23H16N2O）,has been synthesized by the condensation of 4-methylbenzohydrazide and anthracene-9-carbaldehyde in an ethanol solution with chloramine-T.The compound was characterized by 1H-NMR,13C-NMR,MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P with a = 7.7817（4）,b = 8.8544（5）,c = 12.4726（8） ,β = 92.8520（10）°,Z = 2,V = 826.58（8） 3,Dc = 1.352 g/cm3,Mr = 336.38,λ（MoKα） = 0.71073 ,μ = 0.084 mm-1,F（000） = 352,R = 0.0381 and wR = 0.1099.The dihedral angle between anthracene skeleton and phenyl ring is 64.19°.A total of 6354 unique reflections were collected,of which 3172 with I 〉 2σ（I） were observed.X-ray analysis indicated an offset face-to-face π-π stacking interaction between anthracene skeletons and an offset face-to-face π-π stacking interaction between phenyl ring planes.The novel compound molecules are connected through the offset face-to-face π-π stacking interactions to generate a three-dimensional network.The preliminary bioassay results showed that the novel compound exhibited significant insect growth inhibitory activity against Spodoptera litura Fabricius larvae.展开更多
An expeditious microwave-accelerated one-step synthesis of some new 2-（3,5-dimethoxy-4-methylphenyl）-5-aryl-1,3,4- oxadiazoles by reaction of 3,5-dimethoxy-4-methyl hydrazide with different carboxylic acids in prese...An expeditious microwave-accelerated one-step synthesis of some new 2-（3,5-dimethoxy-4-methylphenyl）-5-aryl-1,3,4- oxadiazoles by reaction of 3,5-dimethoxy-4-methyl hydrazide with different carboxylic acids in presence of thionyl chloride under neat conditions,has been achieved.展开更多
The effects of pressure on the fluorescence emission and Raman spectra of 1,4-bis[（4-methyloxyphenyl）-1,3,4-oxadiazolyl]- 2,5-bisheptyloxyphenylene （OXD-2） and on the fluorescence emission spectra of 1,4-bis[（4-m...The effects of pressure on the fluorescence emission and Raman spectra of 1,4-bis[（4-methyloxyphenyl）-1,3,4-oxadiazolyl]- 2,5-bisheptyloxyphenylene （OXD-2） and on the fluorescence emission spectra of 1,4-bis[（4-methylphenyl）- 1,3,4-oxadiazolyl]phenylene （OXD-1） are investigated using a diamond anvil cell. With the increase of pressure, the intensity of the fluorescence emission increases and reaches maxima at 13GPa for OXD-1 and at 9.6GPa for OXD-2. The effect of pressure on the peak position of the emission shows a similar trend, red shift with the increase of pressure. But at higher pressures, the intensity of emission drops down dramatically. The Raman spectra of OXD-2 indicate that there appears a structural change at ca 3GPa.展开更多
Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioet...Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.展开更多
The title compound 2-（（2-fluorobenzyl）thio）-5-（pyridin-4-yl）-1,3,4-oxadiazole（C_（14）H_（10）FN_3OS） was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It ...The title compound 2-（（2-fluorobenzyl）thio）-5-（pyridin-4-yl）-1,3,4-oxadiazole（C_（14）H_（10）FN_3OS） was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541（16）,b = 8.226（12）,c = 13.683（19） ？,β = 94.872（17）o,V = 1294（3） ？~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ（I）. The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.展开更多
Aim To optimize the reaction condition for preparation of 3-spiro-1, 3, 4-oxadiazole substituted fructose and hydrolysis of its isopropylidenes stepwisely. Methods Cyclohexane was added to the reaction mixture every 8...Aim To optimize the reaction condition for preparation of 3-spiro-1, 3, 4-oxadiazole substituted fructose and hydrolysis of its isopropylidenes stepwisely. Methods Cyclohexane was added to the reaction mixture every 8 h to remove acetic acid at 90 ℃. The isopropylidenes were hydrolyzed in 80% AcOH at 60 ℃ stepwisely in a reaction time- dependent manner. Results The yields of cyclization products 1b and 1c were improved from 53% and 51% to 74% and 79% respectively. The 1, 2-di-O-isopropylidene product 3 was obtained after 1 h and the total deprotected product 4 was obtained after 3 h in 80% AcOH at 60 ℃. Conclusion The yield of 1 is improved by cyclohexane-aided azeotropic removal of AcOH from the reaction mixture. Deprotection of 1 in 80% AcOH at 60 ℃ gives 3 or 4 after different time periods.展开更多
Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-（2-chloro-4-methyl-6-phenylpyri...Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-（2-chloro-4-methyl-6-phenylpyrimidin-5-yl）-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575（11）, b = 8.2115（5）, c = 21.2035（12）A, V = 3335.6（3）A3 and Z = 4. Compound 6, 5-（2,6-dichloropyrimidin-4-yl）-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275（13）, b = 5.4088（8）, c = 13.493（2）A, β = 99.768（3）°, V = 4658.6（6）A3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities.展开更多
Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-...Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2（CF_3SO_3）_2]（I） and a coordination polymer [Ag L（PF_6）]_n（Ⅱ）,respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.展开更多
2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, sh...2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, short reaction time （10-15 min）, mild condition, and easy work-up are advantages of this methodology.展开更多
A series of novel 2,5-disubstituted-1,3,4-oxadiazoles have been synthesized from long-chain alkanoic and alkenoic acids. The structures of these compounds have been elucidated by elemental and spectral （IR, ^1H NMR, ...A series of novel 2,5-disubstituted-1,3,4-oxadiazoles have been synthesized from long-chain alkanoic and alkenoic acids. The structures of these compounds have been elucidated by elemental and spectral （IR, ^1H NMR, ^13C NMR, MS） analysis. Furthermore, compounds were screened for in vitro antibacterial activity against the representative panel of two Gram-positive and two Gram- negative bacteria. All the synthesized compounds were also tested for their inhibitory action against five strains of fungus. The various compounds show potent inhibitory action against test organisms. 2007 Abdul Rauf. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
基金The National Basic Research Program of China(973Program)(No.2007CB936300)the High Technology Research and Devel-opment Program of Jiangsu Province(No.BG2006033).
文摘A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synthesized by Heck coupling reaction and characterized with UV-vis, Fourier transform infrared （ FT-IR ）, ^1H-NMR and photoluminescence （ PL ） spectroscopy, oxa-MEHPV possesses an outstanding thermal stability and shows excellent solubility in common organic solvents such as dichloromethane, chloroform, toluene, and tetrahydrofuran（THF）. The introduction of the electron-deficient 1, 3, 4-oxadiazole units into the MEH-PPV backbone also increases the electron affinities of the conjugated segment, which leads to the blue-shift of the maximum absorption wavelength and makes the polymer have a high optical band-gap energy, good electron-transporting stability and high PL quantum yield.
文摘1、2－O－Isopropylidene－3－C－cyano－5－O－benzoyl－α－D－xylose 2 was preparedstereoselectively from 1，2－O－isopropylidene－3－oxo－5－O－benzoyl－α－D－xylose 1．The structure of 2was studied by two－dimensional NMR spectroscopy in conjunction with X－ray crystallography of itscorresponding 5－phenyl－1，2，4－oxadiazole isocarbonucleoside derivative 3． The absoluteconfigurations of 2 and 3，and conformation of 3 are described herein．
基金This work was supported by the National Natural Science Foundation of China(No.20272014)the Project of National Education Ministry(Project No.204097)National 973 Project of China(Project No.2002CB613400-5).
文摘A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesizedand characterized. Its UV and photoluminescent properties were studied. The strong UVabsorption intensity around 462 nm attributed to spin-forbidden triplet metal–ligand charge transferband and photoluminescence at 518 nm were observed. This indicated that achieved iridiumcomplex could be used as an efficient electrophosphorescent material.
基金Supported by the National Natural Science Foundation of China (10874047)Natural Science Foundation of Guangdong Province (04300531)
文摘A novel compound,2-（anthracen-9-yl）-5-p-tolyl-1,3,4-oxadiazole（C23H16N2O）,has been synthesized by the condensation of 4-methylbenzohydrazide and anthracene-9-carbaldehyde in an ethanol solution with chloramine-T.The compound was characterized by 1H-NMR,13C-NMR,MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P with a = 7.7817（4）,b = 8.8544（5）,c = 12.4726（8） ,β = 92.8520（10）°,Z = 2,V = 826.58（8） 3,Dc = 1.352 g/cm3,Mr = 336.38,λ（MoKα） = 0.71073 ,μ = 0.084 mm-1,F（000） = 352,R = 0.0381 and wR = 0.1099.The dihedral angle between anthracene skeleton and phenyl ring is 64.19°.A total of 6354 unique reflections were collected,of which 3172 with I 〉 2σ（I） were observed.X-ray analysis indicated an offset face-to-face π-π stacking interaction between anthracene skeletons and an offset face-to-face π-π stacking interaction between phenyl ring planes.The novel compound molecules are connected through the offset face-to-face π-π stacking interactions to generate a three-dimensional network.The preliminary bioassay results showed that the novel compound exhibited significant insect growth inhibitory activity against Spodoptera litura Fabricius larvae.
文摘An expeditious microwave-accelerated one-step synthesis of some new 2-（3,5-dimethoxy-4-methylphenyl）-5-aryl-1,3,4- oxadiazoles by reaction of 3,5-dimethoxy-4-methyl hydrazide with different carboxylic acids in presence of thionyl chloride under neat conditions,has been achieved.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10104008, 29974013, 50373016 ）, the International Science and Technology Cooperation Project of China （Grant No 2001CB711201） and the State Education Commission Foundation for Excellent Young Teachers of China.
文摘The effects of pressure on the fluorescence emission and Raman spectra of 1,4-bis[（4-methyloxyphenyl）-1,3,4-oxadiazolyl]- 2,5-bisheptyloxyphenylene （OXD-2） and on the fluorescence emission spectra of 1,4-bis[（4-methylphenyl）- 1,3,4-oxadiazolyl]phenylene （OXD-1） are investigated using a diamond anvil cell. With the increase of pressure, the intensity of the fluorescence emission increases and reaches maxima at 13GPa for OXD-1 and at 9.6GPa for OXD-2. The effect of pressure on the peak position of the emission shows a similar trend, red shift with the increase of pressure. But at higher pressures, the intensity of emission drops down dramatically. The Raman spectra of OXD-2 indicate that there appears a structural change at ca 3GPa.
基金We gratefully acknowledge the financial support of the Natural Science Foundation of Education Department of Hubei Province （No. 2004D001）.
文摘Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.
基金funded by the Natural Science Foundation of Zhejiang Province(No.LY16C140007)the program of Science and Technology of Jiangsu Province(BY2014108-14)
文摘The title compound 2-（（2-fluorobenzyl）thio）-5-（pyridin-4-yl）-1,3,4-oxadiazole（C_（14）H_（10）FN_3OS） was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541（16）,b = 8.226（12）,c = 13.683（19） ？,β = 94.872（17）o,V = 1294（3） ？~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ（I）. The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.
文摘Aim To optimize the reaction condition for preparation of 3-spiro-1, 3, 4-oxadiazole substituted fructose and hydrolysis of its isopropylidenes stepwisely. Methods Cyclohexane was added to the reaction mixture every 8 h to remove acetic acid at 90 ℃. The isopropylidenes were hydrolyzed in 80% AcOH at 60 ℃ stepwisely in a reaction time- dependent manner. Results The yields of cyclization products 1b and 1c were improved from 53% and 51% to 74% and 79% respectively. The 1, 2-di-O-isopropylidene product 3 was obtained after 1 h and the total deprotected product 4 was obtained after 3 h in 80% AcOH at 60 ℃. Conclusion The yield of 1 is improved by cyclohexane-aided azeotropic removal of AcOH from the reaction mixture. Deprotection of 1 in 80% AcOH at 60 ℃ gives 3 or 4 after different time periods.
基金supported by the National Natural Science Foundation of China(Nos.81302629,21172088)
文摘Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-（2-chloro-4-methyl-6-phenylpyrimidin-5-yl）-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575（11）, b = 8.2115（5）, c = 21.2035（12）A, V = 3335.6（3）A3 and Z = 4. Compound 6, 5-（2,6-dichloropyrimidin-4-yl）-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275（13）, b = 5.4088（8）, c = 13.493（2）A, β = 99.768（3）°, V = 4658.6（6）A3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities.
基金financially supported by the National Natural Science Foundation of China(No.21201112)
文摘Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2（CF_3SO_3）_2]（I） and a coordination polymer [Ag L（PF_6）]_n（Ⅱ）,respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.
文摘2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, short reaction time （10-15 min）, mild condition, and easy work-up are advantages of this methodology.
文摘A series of novel 2,5-disubstituted-1,3,4-oxadiazoles have been synthesized from long-chain alkanoic and alkenoic acids. The structures of these compounds have been elucidated by elemental and spectral （IR, ^1H NMR, ^13C NMR, MS） analysis. Furthermore, compounds were screened for in vitro antibacterial activity against the representative panel of two Gram-positive and two Gram- negative bacteria. All the synthesized compounds were also tested for their inhibitory action against five strains of fungus. The various compounds show potent inhibitory action against test organisms. 2007 Abdul Rauf. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
