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2010 Volume 21 Issue 11
2010, 21(11): 1267-1269
doi: 10.1016/j.cclet.2010.06.037
Abstract:
A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids, (±)-puyanin 1 and (±)-4'-O-methylbonannione 2 has been obtained with total yield 27% and 21%, respectively. The key steps were regioseleetive cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2, 4, 6-trihydroxyacetophenone.
A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids, (±)-puyanin 1 and (±)-4'-O-methylbonannione 2 has been obtained with total yield 27% and 21%, respectively. The key steps were regioseleetive cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2, 4, 6-trihydroxyacetophenone.
2010, 21(11): 1270-1272
doi: 10.1016/j.cclet.2010.05.030
Abstract:
A new method is described to synthesize phendione derivatives from 1, 10-phenanthrolines using potassium bromate and 60%sulfuric acid as oxidant, which was easily applicable to scale-up. The reaction conditions are mild and the yields are excellent. The target compounds have been characterized by 1H NMR, and IR.
A new method is described to synthesize phendione derivatives from 1, 10-phenanthrolines using potassium bromate and 60%sulfuric acid as oxidant, which was easily applicable to scale-up. The reaction conditions are mild and the yields are excellent. The target compounds have been characterized by 1H NMR, and IR.
2010, 21(11): 1273-1276
doi: 10.1016/j.cclet.2010.07.001
Abstract:
New D-seco-taxoids were synthesized from 1-deoxybaccatin Ⅵ and their structures were confirmed by 1H NMR, 13C NMR, ESIMS and X-ray crystallography. The key step of the synthesis involved the opening of the oxetane ring under acid and basic conditions in order to obtain new multidrug resistance (MDR) reversal agents and new synthetic precursors of paclitaxel analogues.
New D-seco-taxoids were synthesized from 1-deoxybaccatin Ⅵ and their structures were confirmed by 1H NMR, 13C NMR, ESIMS and X-ray crystallography. The key step of the synthesis involved the opening of the oxetane ring under acid and basic conditions in order to obtain new multidrug resistance (MDR) reversal agents and new synthetic precursors of paclitaxel analogues.
2010, 21(11): 1277-1280
doi: 10.1016/j.cclet.2010.07.013
Abstract:
A simple, highly effective hydrogenation of chiral BINOL to provide H4-BINOL in multigram scale with good yield (up to 78% yield) was developed. A series of heterogeneous catalysts was tested in the hydrogenation; the best result was obtained with 5% Pd/C in EtOH under the H2 pressure of 50 bar for 2 h. This method is a more useful method for practical synthesis of optically pure H4-BINOL than other available methods.
A simple, highly effective hydrogenation of chiral BINOL to provide H4-BINOL in multigram scale with good yield (up to 78% yield) was developed. A series of heterogeneous catalysts was tested in the hydrogenation; the best result was obtained with 5% Pd/C in EtOH under the H2 pressure of 50 bar for 2 h. This method is a more useful method for practical synthesis of optically pure H4-BINOL than other available methods.
2010, 21(11): 1281-1282
doi: 10.1016/j.cclet.2010.05.019
Abstract:
8-Oxocoptisine 1, a natural protoberberine alkaloid, can be more easily achieved starting from readily available and inexpensive berberine hydrochlorate 2. The structure of the target compound 1 was confirmed by melting point, 1H NMR, IR, MS and elemental analysis.
8-Oxocoptisine 1, a natural protoberberine alkaloid, can be more easily achieved starting from readily available and inexpensive berberine hydrochlorate 2. The structure of the target compound 1 was confirmed by melting point, 1H NMR, IR, MS and elemental analysis.
2010, 21(11): 1283-1286
doi: 10.1016/j.cclet.2010.05.016
Abstract:
A mild, efficient and regioselective method for the mononitration of phenolic compounds is described using bismuth subnitrate/charcoal in the presence of trichloroisocyanuric acid in CH2Cl2 at room temperature.
A mild, efficient and regioselective method for the mononitration of phenolic compounds is described using bismuth subnitrate/charcoal in the presence of trichloroisocyanuric acid in CH2Cl2 at room temperature.
2010, 21(11): 1287-1290
doi: 10.1016/j.cclet.2010.05.015
Abstract:
An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethy-lammonium cerium nitrate at room temperature is described. Reaction was completed within short time period in high yields at room temperature.
An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethy-lammonium cerium nitrate at room temperature is described. Reaction was completed within short time period in high yields at room temperature.
2010, 21(11): 1291-1294
doi: 10.1016/j.cclet.2010.04.030
Abstract:
An unexpected reaction of 10-bromomethyl-12-oxocalanolide A (2) with primary amine was demonstrated and studied. Consequentially, a new method for the preparation of N-substituted pyrroles starting from γ-halo-α, β-unsaturated ketone was presented.
An unexpected reaction of 10-bromomethyl-12-oxocalanolide A (2) with primary amine was demonstrated and studied. Consequentially, a new method for the preparation of N-substituted pyrroles starting from γ-halo-α, β-unsaturated ketone was presented.
2010, 21(11): 1295-1298
doi: 10.1016/j.cclet.2010.04.034
Abstract:
A series of novel coumarin-stilbenes hybrids called 3-arylcoumarins were synthesized via Perkin reaction and evaluated as potential antitumor agents. The results showed that some compounds exhibited in vitro activity against KB, KV, MCF-7, MCF-7/ADR cell lines to some extent. Compound 3a showed remarkable effect against KB tumor cells with an IC50 value of 5.18 μmol/L.
A series of novel coumarin-stilbenes hybrids called 3-arylcoumarins were synthesized via Perkin reaction and evaluated as potential antitumor agents. The results showed that some compounds exhibited in vitro activity against KB, KV, MCF-7, MCF-7/ADR cell lines to some extent. Compound 3a showed remarkable effect against KB tumor cells with an IC50 value of 5.18 μmol/L.
2010, 21(11): 1299-1302
doi: 10.1016/j.cclet.2010.06.008
Abstract:
Oligo (methylsilylene)-ethynylene polymer with erosslinkable ethynyl unit in the main chain was synthesized by condensation of α, ω-dicholorooligo (methylsilane) with dilithioacetylene. The as-synthesized polymer was characterized by GPC, FT-IR and NMR. The results showed ethynyl group was successfully introduced to the polymer main chain. The ceramic yield was dramatically increased by the cross-polymerization of ethynyl group, and the excess silicon of PMS was compensated. Nearstoichiometric (C/Si=1.17) and partial crystallization β-SiC monoliths were obtained by pressureless pyrolysing PSPA at 1200℃in a high yield (73.6 wt%).
Oligo (methylsilylene)-ethynylene polymer with erosslinkable ethynyl unit in the main chain was synthesized by condensation of α, ω-dicholorooligo (methylsilane) with dilithioacetylene. The as-synthesized polymer was characterized by GPC, FT-IR and NMR. The results showed ethynyl group was successfully introduced to the polymer main chain. The ceramic yield was dramatically increased by the cross-polymerization of ethynyl group, and the excess silicon of PMS was compensated. Nearstoichiometric (C/Si=1.17) and partial crystallization β-SiC monoliths were obtained by pressureless pyrolysing PSPA at 1200℃in a high yield (73.6 wt%).
2010, 21(11): 1303-1306
doi: 10.1016/j.cclet.2010.06.009
Abstract:
Two cobalt (Ⅱ) complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH, solvent, temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes. Under obtained optimum conditions, various alcohols were oxidized to corresponding aldehydes and ketones.
Two cobalt (Ⅱ) complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH, solvent, temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes. Under obtained optimum conditions, various alcohols were oxidized to corresponding aldehydes and ketones.
2010, 21(11): 1307-1309
doi: 10.1016/j.cclet.2010.05.012
Abstract:
Hyrtiosulawesine was isolated from Indonesian specimens of the marine sponges Hyrtios erectus and H. reticulatu in 2002. We report here the first total synthesis of hyrtiosulawesine using an efficient and convenient synthetic strategy which could be widely used in the synthesis of other β-carboline compounds. All structures of new compounds were confirmed by 1H NMR, 13C NMR and HRMS.
Hyrtiosulawesine was isolated from Indonesian specimens of the marine sponges Hyrtios erectus and H. reticulatu in 2002. We report here the first total synthesis of hyrtiosulawesine using an efficient and convenient synthetic strategy which could be widely used in the synthesis of other β-carboline compounds. All structures of new compounds were confirmed by 1H NMR, 13C NMR and HRMS.
2010, 21(11): 1310-1313
doi: 10.1016/j.cclet.2010.06.007
Abstract:
The hydrosilylation of alkenes with triethoxysilane has been achieved at 120℃ in the presence of 0.01 mol% of thioether-functionalized MCM-41 anchored rhodium complex, affording the corresponding addition products in 68-91% yields. This supported rhodium complex can be reused several times without noticeable loss of activity. Our system not only solves the basic problems of catalyst separation and recovery, hat also avoids the use of phosphine ligands.
The hydrosilylation of alkenes with triethoxysilane has been achieved at 120℃ in the presence of 0.01 mol% of thioether-functionalized MCM-41 anchored rhodium complex, affording the corresponding addition products in 68-91% yields. This supported rhodium complex can be reused several times without noticeable loss of activity. Our system not only solves the basic problems of catalyst separation and recovery, hat also avoids the use of phosphine ligands.
2010, 21(11): 1314-1317
doi: 10.1016/j.cclet.2010.05.029
Abstract:
The metal-free combination of catalytic amounts of PPh3, B(C6F5)3, and PhSiH3 can efficiently hydrosilylate aldehydes, ketones, aldimines and ketimines to afford the corresponding reduction products in good yields.
The metal-free combination of catalytic amounts of PPh3, B(C6F5)3, and PhSiH3 can efficiently hydrosilylate aldehydes, ketones, aldimines and ketimines to afford the corresponding reduction products in good yields.
2010, 21(11): 1318-1321
doi: 10.1016/j.cclet.2010.06.023
Abstract:
A serials of novel 5-substituted benzyl-2, 4-diamino pyrimidine derivatives have been synthesized and evaluated as inhibitors of c-Fms kinase by the standard MTT method. The results showed that compound 15, 5-[3-methoxy-4-(pyridine-3-yl) benzyl]-2, 4-diamino pyrimidine, had an IC50 of 1.45 μmol/L in inhibiting the proliferation of M-CSF-dependent myeloid leukemia cells in mice (NFS-60), which was similar with GW2580, a selective inhibitor of c-Fms kinase.
A serials of novel 5-substituted benzyl-2, 4-diamino pyrimidine derivatives have been synthesized and evaluated as inhibitors of c-Fms kinase by the standard MTT method. The results showed that compound 15, 5-[3-methoxy-4-(pyridine-3-yl) benzyl]-2, 4-diamino pyrimidine, had an IC50 of 1.45 μmol/L in inhibiting the proliferation of M-CSF-dependent myeloid leukemia cells in mice (NFS-60), which was similar with GW2580, a selective inhibitor of c-Fms kinase.
2010, 21(11): 1322-1325
doi: 10.1016/j.cclet.2010.06.042
Abstract:
Au/FeOx-TiO2, prepared by deposition-precipitation method, is an efficient and stable catalyst for the liquid phase selective hydrogenation of phthalic anhydride to phthalide under mild reaction conditions.
Au/FeOx-TiO2, prepared by deposition-precipitation method, is an efficient and stable catalyst for the liquid phase selective hydrogenation of phthalic anhydride to phthalide under mild reaction conditions.
2010, 21(11): 1326-1326
doi: 10.1016/j.cclet.2010.05.011
Abstract:
A series of 1H-benzimidazol-5-ol derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and eytotoxicity in HepG2.2.15 cells. Half of the tested compounds were found to be potent against HBsAg secretion with IC50 values less than 100 μmol/L. Compounds 14c, 14d, and 14e showed significant inhibitory activity to the viral antigen HBeAg.
A series of 1H-benzimidazol-5-ol derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and eytotoxicity in HepG2.2.15 cells. Half of the tested compounds were found to be potent against HBsAg secretion with IC50 values less than 100 μmol/L. Compounds 14c, 14d, and 14e showed significant inhibitory activity to the viral antigen HBeAg.
2010, 21(11): 1330-1333
doi: 10.1016/j.cclet.2010.05.010
Abstract:
A new approach to synthesize liquid crystalline polymer with narrow polydispersity index (PDI) was developed. Photo-polymerization of 4-cyanophenyl-4'-(6-acryloyloxyhexyloxy) benzoate(RM23)in nematic liquid crystals with macroscopic orientation was studied. The effects of the monomer concentration on the molecular weight and PDI of the resulting polymers were studied through gel permeation chromatography(GPC)and polarized optical microscopy. The low PDI of 1.19 and 1.22 was obtained in the reverse and normal modes, respectively. The PDI and molecular weight increased with monomer concentration.
A new approach to synthesize liquid crystalline polymer with narrow polydispersity index (PDI) was developed. Photo-polymerization of 4-cyanophenyl-4'-(6-acryloyloxyhexyloxy) benzoate(RM23)in nematic liquid crystals with macroscopic orientation was studied. The effects of the monomer concentration on the molecular weight and PDI of the resulting polymers were studied through gel permeation chromatography(GPC)and polarized optical microscopy. The low PDI of 1.19 and 1.22 was obtained in the reverse and normal modes, respectively. The PDI and molecular weight increased with monomer concentration.
2010, 21(11): 1334-1337
doi: 10.1016/j.cclet.2010.06.022
Abstract:
Dihydrotetrabenazine (DTBZ) is the major pharmacologically active form of tetrabenazine (TBZ), which was approved by FDA for the treatment of chorea associated with Huntington's disease (HD). An unexpected Hoffmann elimination was observed during the treatment of DTBZ with sodium hydrogen and alkyl halides, leading to the formation of both eliminated products (major) and hydroxyl-alkylated products (minor).
Dihydrotetrabenazine (DTBZ) is the major pharmacologically active form of tetrabenazine (TBZ), which was approved by FDA for the treatment of chorea associated with Huntington's disease (HD). An unexpected Hoffmann elimination was observed during the treatment of DTBZ with sodium hydrogen and alkyl halides, leading to the formation of both eliminated products (major) and hydroxyl-alkylated products (minor).
2010, 21(11): 1338-1341
doi: 10.1016/j.cclet.2010.06.021
Abstract:
A versatile synthesis of novel zanamivir analogues modified at C-4 and C-8 positions was described. The formation of amides from the acid with corresponding amines, followed by click chemistry generated the triazole substituted compounds as novel analogues of neuraminidase inhibitors in good yields.
A versatile synthesis of novel zanamivir analogues modified at C-4 and C-8 positions was described. The formation of amides from the acid with corresponding amines, followed by click chemistry generated the triazole substituted compounds as novel analogues of neuraminidase inhibitors in good yields.
2010, 21(11): 1342-1345
doi: 10.1016/j.cclet.2010.05.028
Abstract:
Benzyltripbenylphosphonium tribromide (BTPTB) has been applied as an efficient catalyst for the preparation of bis (indolyl) methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.
Benzyltripbenylphosphonium tribromide (BTPTB) has been applied as an efficient catalyst for the preparation of bis (indolyl) methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.
2010, 21(11): 1346-1349
doi: 10.1016/j.cclet.2010.06.028
Abstract:
An efficient one-pot synthesis of 2, 4, 6-triarylpyridines has been described. This involves the three-component reaction of aldehydes, ketones and ammonium acetate in the presence of a catalytic amount of wet 2, 4, 6-trichloro-1, 3, 5-triazine(TCT)under solvent-free condition at 130℃.
An efficient one-pot synthesis of 2, 4, 6-triarylpyridines has been described. This involves the three-component reaction of aldehydes, ketones and ammonium acetate in the presence of a catalytic amount of wet 2, 4, 6-trichloro-1, 3, 5-triazine(TCT)under solvent-free condition at 130℃.
2010, 21(11): 1350-1351
doi: 10.1016/j.cclet.2010.06.033
Abstract:
A new flavonoid was isolated from the bract of Zea mays L. The structure of the compound was identified as 4',5,7-trihydroxy-3',5'-dimethoxyflavone 7-O-[β-D-apiofuranosyl(1→2)]-β-D-glucopyranoside on the ground of chemical and spectroscopic methods.
A new flavonoid was isolated from the bract of Zea mays L. The structure of the compound was identified as 4',5,7-trihydroxy-3',5'-dimethoxyflavone 7-O-[β-D-apiofuranosyl(1→2)]-β-D-glucopyranoside on the ground of chemical and spectroscopic methods.
2010, 21(11): 1352-1354
doi: 10.1016/j.cclet.2010.06.027
Abstract:
A new triterpenoid, possessing a lanost-9(11)-3-one skeleton, was isolated from the roots of Kadsura coccinea, based on the spectral analysis, its structure was elucidated as 3-hydroxy-12-acetoxycoccinic acid.
A new triterpenoid, possessing a lanost-9(11)-3-one skeleton, was isolated from the roots of Kadsura coccinea, based on the spectral analysis, its structure was elucidated as 3-hydroxy-12-acetoxycoccinic acid.
2010, 21(11): 1355-1357
doi: 10.1016/j.cclet.2010.06.026
Abstract:
A new nine-membered lactone, cladospolide E(1), was isolated from a culture broth of a marine fungus Cladosporium sp. F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis, including 1D and 2D NMR data.
A new nine-membered lactone, cladospolide E(1), was isolated from a culture broth of a marine fungus Cladosporium sp. F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis, including 1D and 2D NMR data.
2010, 21(11): 1358-1360
doi: 10.1016/j.cclet.2010.04.035
Abstract:
A guanidinium ionic liquid, N, N, N', N'-tetrabexyl-N", N"-dimethylguanidinium bis (trifluoromethane) sulfonylimide (THDMGNTf2), was synthesized and used as stationary phase for capillary gas chromatography. In comparison with imidazolium ionic liquid stationary phase, the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase. The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grob test mixture than irnidazolium ionic liquid of 1-octyl-3-butylimidazolium bis (trifluoromethane) sulfonylimide (OBIM-NTf2). Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2. Additionally, essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components. Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column (10 m) while using a commercial column(30 m)as reference. The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.
A guanidinium ionic liquid, N, N, N', N'-tetrabexyl-N", N"-dimethylguanidinium bis (trifluoromethane) sulfonylimide (THDMGNTf2), was synthesized and used as stationary phase for capillary gas chromatography. In comparison with imidazolium ionic liquid stationary phase, the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase. The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grob test mixture than irnidazolium ionic liquid of 1-octyl-3-butylimidazolium bis (trifluoromethane) sulfonylimide (OBIM-NTf2). Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2. Additionally, essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components. Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column (10 m) while using a commercial column(30 m)as reference. The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.
2010, 21(11): 1361-1365
doi: 10.1016/j.cclet.2010.05.014
Abstract:
A rapid, simple, and reliable competitive molecular imprinted polymer sorbent assay (MIPSA) was developed and validated for measurement of parathion in water samples. This assay employed a molecular imprinted polymer (MIP) that was synthesized with non-covalent imprinting method as capture reagent and p-aminoparathion conjugate of horseradish peroxidase(para-HRP)as an enzyme label. The assay depended on a competitive binding reaction between the enzyme conjugate and analyte for the binding sites of the MIE The optimized analysis conditions of 10 ng mL-1 para-HRP and 10 mg mL-1 polymer were found. The assay was acceptable to detect parathion in water samples under the optimized conditions, with a limit of detection of 50 ng mL-1. Mean analytical recoveries of added parathion in water samples ranged from 101.2% to 105%. The precision of the assay was satisfactory;relative standard deviation ranged from 4.3% to 6%.
A rapid, simple, and reliable competitive molecular imprinted polymer sorbent assay (MIPSA) was developed and validated for measurement of parathion in water samples. This assay employed a molecular imprinted polymer (MIP) that was synthesized with non-covalent imprinting method as capture reagent and p-aminoparathion conjugate of horseradish peroxidase(para-HRP)as an enzyme label. The assay depended on a competitive binding reaction between the enzyme conjugate and analyte for the binding sites of the MIE The optimized analysis conditions of 10 ng mL-1 para-HRP and 10 mg mL-1 polymer were found. The assay was acceptable to detect parathion in water samples under the optimized conditions, with a limit of detection of 50 ng mL-1. Mean analytical recoveries of added parathion in water samples ranged from 101.2% to 105%. The precision of the assay was satisfactory;relative standard deviation ranged from 4.3% to 6%.
2010, 21(11): 1366-1369
doi: 10.1016/j.cclet.2010.06.025
Abstract:
LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane, giving 84% ethane conversion and 74% ethene yield at 923 K. Results indicated that the stronger the basicity of LiCl-based catalysts, the better the catalytic performance.
LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane, giving 84% ethane conversion and 74% ethene yield at 923 K. Results indicated that the stronger the basicity of LiCl-based catalysts, the better the catalytic performance.
2010, 21(11): 1370-1373
doi: 10.1016/j.cclet.2010.05.013
Abstract:
A novel star-comb styrene/butadiene copolymer (SC-SBC) was synthesized by anionic polymerization and grafting reaction with epoxidized star liquid polybutadiene (ESPB) as coupling agent. The overall shape of the star-comb macromolecules can be altered by changing the molecular weight and number of the side chain. The molecular parameters and mechanical properties of the SC-SBC resins were investigated. The notched izod impact strength of the SC-SBC resins are excellent and reach as high as to 239 J/m.
A novel star-comb styrene/butadiene copolymer (SC-SBC) was synthesized by anionic polymerization and grafting reaction with epoxidized star liquid polybutadiene (ESPB) as coupling agent. The overall shape of the star-comb macromolecules can be altered by changing the molecular weight and number of the side chain. The molecular parameters and mechanical properties of the SC-SBC resins were investigated. The notched izod impact strength of the SC-SBC resins are excellent and reach as high as to 239 J/m.
2010, 21(11): 1374-1377
doi: 10.1016/j.cclet.2010.06.031
Abstract:
A series of linear and X-shaped oligo (para-phenylene) derivatives functionalized with fluorene ethynylenes 1, 3 and 4 were synthesized through sequent Sonogashira coupling and Suzuki-Miyaura reaction in high yield. The electron-donating group -OCH3 and electron-withdrawing counterparts -CF3 were introduced to tune the spectra properties of compounds 3 and 4. The detail investigation of their photophysical properties in solution and film indicated that the introduction of both-OCH3 and -CF3 makes maximum emission distinct red-shift in comparison with parent compound 1, but the latter more prominently.
A series of linear and X-shaped oligo (para-phenylene) derivatives functionalized with fluorene ethynylenes 1, 3 and 4 were synthesized through sequent Sonogashira coupling and Suzuki-Miyaura reaction in high yield. The electron-donating group -OCH3 and electron-withdrawing counterparts -CF3 were introduced to tune the spectra properties of compounds 3 and 4. The detail investigation of their photophysical properties in solution and film indicated that the introduction of both-OCH3 and -CF3 makes maximum emission distinct red-shift in comparison with parent compound 1, but the latter more prominently.
2010, 21(11): 1378-1381
doi: 10.1016/j.cclet.2010.06.003
Abstract:
A novel potentiometric detection strategy based on functionalized magnetic nanoparticles has been developed for rapid and sensitive sensing of polyions. Highly dispersed magnetic nanoparticles coated with ion exchanger and plasticizer could promote an in situ cooperative ion-pairing interaction between the ion exchanger and the polyion analyte in sample solution by dramatically reducing the mass-transfer distance. With applying a magnetic field, the nanoparticles can be attached to the surface of ion exchanger free polymeric membrane. The observed potential signals are related to the polyion concentrations. The proposed polymeric membrane electrode exhibits a linear relationship between the greatest potential response slope (dE/dt) and the logarithm of protamine concentration in the range of 0.05-5 μg/mL with a lower detection limit of 0.033 μg/mL.
A novel potentiometric detection strategy based on functionalized magnetic nanoparticles has been developed for rapid and sensitive sensing of polyions. Highly dispersed magnetic nanoparticles coated with ion exchanger and plasticizer could promote an in situ cooperative ion-pairing interaction between the ion exchanger and the polyion analyte in sample solution by dramatically reducing the mass-transfer distance. With applying a magnetic field, the nanoparticles can be attached to the surface of ion exchanger free polymeric membrane. The observed potential signals are related to the polyion concentrations. The proposed polymeric membrane electrode exhibits a linear relationship between the greatest potential response slope (dE/dt) and the logarithm of protamine concentration in the range of 0.05-5 μg/mL with a lower detection limit of 0.033 μg/mL.
2010, 21(11): 1382-1386
doi: 10.1016/j.cclet.2010.04.039
Abstract:
LiMn2O4 spinel cathode materials were modified with 2 wt.% Li-M-PO4 (M=Co, Ni, Mn) by polyol synthesis method. The phosphate surface-modified LiMn2O4 cathode materials were physically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The charge-discharge test showed that the cycling and rate capacities of LiMn2O4 cathode materials were significantly enhanced by stabilizing the electrode surface with phosphate.
LiMn2O4 spinel cathode materials were modified with 2 wt.% Li-M-PO4 (M=Co, Ni, Mn) by polyol synthesis method. The phosphate surface-modified LiMn2O4 cathode materials were physically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The charge-discharge test showed that the cycling and rate capacities of LiMn2O4 cathode materials were significantly enhanced by stabilizing the electrode surface with phosphate.
2010, 21(11): 1387-1390
doi: 10.1016/j.cclet.2010.05.033
Abstract:
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 AgNO3 was used as the source of the silver particles. Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of his (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.
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 AgNO3 was used as the source of the silver particles. Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of his (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.
