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2007 Volume 18 Issue 5
2007, 18(5): 499-501
doi: 10.1016/j.cclet.2007.03.002
Abstract:
N, N'-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.
N, N'-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.
2007, 18(5): 502-504
doi: 10.1016/j.cclet.2007.03.022
Abstract:
A Nafion-H catalyzed, single step and environmentally friendly process for synthesis of dihydropyrimidinones is described. This adopted protocol for Biginelli reaction has the advantages of reusability of the catalyst, high yields and ease of separation of pure products.
A Nafion-H catalyzed, single step and environmentally friendly process for synthesis of dihydropyrimidinones is described. This adopted protocol for Biginelli reaction has the advantages of reusability of the catalyst, high yields and ease of separation of pure products.
2007, 18(5): 505-508
doi: 10.1016/j.cclet.2007.03.001
Abstract:
By the condensation of 2, 6-bis (4-amino-5-mercapto-[1, 2, 4]-triazoles-2) pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2, 6-bis (6-aryl-[1, 2, 4]-triazolo[3, 4-b] [1, 3, 4]-thiadiazole-3-yl) pyridines were synthesized.Their structures were confirmed by IR, 1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.
By the condensation of 2, 6-bis (4-amino-5-mercapto-[1, 2, 4]-triazoles-2) pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2, 6-bis (6-aryl-[1, 2, 4]-triazolo[3, 4-b] [1, 3, 4]-thiadiazole-3-yl) pyridines were synthesized.Their structures were confirmed by IR, 1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.
2007, 18(5): 509-512
doi: 10.1016/j.cclet.2007.03.004
Abstract:
A novel anthraquinone phthalocyanine Al (Ⅲ) 4 and Co (Ⅱ) 5 were synthesized and characterized by elemental analysis, IR, UV/vis, 1H NMR, HPLC and MS. The photophysical properties of the two metal complexes were studied and compared by fluorescence spectrum method.
A novel anthraquinone phthalocyanine Al (Ⅲ) 4 and Co (Ⅱ) 5 were synthesized and characterized by elemental analysis, IR, UV/vis, 1H NMR, HPLC and MS. The photophysical properties of the two metal complexes were studied and compared by fluorescence spectrum method.
2007, 18(5): 513-515
doi: 10.1016/j.cclet.2007.03.018
Abstract:
A novel bifunctional compound carrying cluster thiogalactoside as the cell targeting ligands was synthesized for gene delivery to hepatocytes. Tetra-antennary dendr-OMs45 was used as a scaffold for the attachment of three galactosides, while the other mesylate end was linked with cholesterol through poly (ethylene glycol) chain. This design provided an effective entry for the synthesis of the bifunctional compound.
A novel bifunctional compound carrying cluster thiogalactoside as the cell targeting ligands was synthesized for gene delivery to hepatocytes. Tetra-antennary dendr-OMs45 was used as a scaffold for the attachment of three galactosides, while the other mesylate end was linked with cholesterol through poly (ethylene glycol) chain. This design provided an effective entry for the synthesis of the bifunctional compound.
2007, 18(5): 516-518
doi: 10.1016/j.cclet.2007.03.013
Abstract:
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then (4R)-benzyl azetidine-2-one-4-carboxylate and meso-3, 6-disubstituted piperazine2, 5-diones were synthesized via intramolecular cyclization and intermolecular cyclization of D-dibenzyl aspartate, respectively, and their structures were confirmed by 1H NMR and MS. Both cyclization reaction conditions were also investigated in detail.
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then (4R)-benzyl azetidine-2-one-4-carboxylate and meso-3, 6-disubstituted piperazine2, 5-diones were synthesized via intramolecular cyclization and intermolecular cyclization of D-dibenzyl aspartate, respectively, and their structures were confirmed by 1H NMR and MS. Both cyclization reaction conditions were also investigated in detail.
2007, 18(5): 519-522
doi: 10.1016/j.cclet.2007.03.019
Abstract:
New functionalized spiroxazine containing azo group has been prepared and its photochromic mechanism has been investigated by laser induced time-resolved techniques.
New functionalized spiroxazine containing azo group has been prepared and its photochromic mechanism has been investigated by laser induced time-resolved techniques.
2007, 18(5): 523-526
doi: 10.1016/j.cclet.2007.03.035
Abstract:
A novel phthalonitrile derivative containing an amino group, 3, 5-bis (3, 4-dicyanophenoxy) aniline (CPA), was synthesized via a nucleophilic displacement of 4-nitrophthalonitrile and 5-aminoresorcinol hydrochloride. The structure of CPA was confirmed by Fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (1H NMR). Thermal analysis performed on CPA revealed that the novel phthalonitrile derivative showed a self-promotion curing behavior and the resulting polymer exhibited outstanding heat-resistance.
A novel phthalonitrile derivative containing an amino group, 3, 5-bis (3, 4-dicyanophenoxy) aniline (CPA), was synthesized via a nucleophilic displacement of 4-nitrophthalonitrile and 5-aminoresorcinol hydrochloride. The structure of CPA was confirmed by Fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (1H NMR). Thermal analysis performed on CPA revealed that the novel phthalonitrile derivative showed a self-promotion curing behavior and the resulting polymer exhibited outstanding heat-resistance.
2007, 18(5): 527-529
doi: 10.1016/j.cclet.2007.03.008
Abstract:
A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties.
A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties.
2007, 18(5): 530-532
doi: 10.1016/j.cclet.2007.03.017
Abstract:
A novel compound, (E)-4'-(4-(but-1-en-3-ynyl) phenyl)-2, 2':6', 2"-terpyridine 1 was synthesized from 4'-(4-bromomethylphenyl)-2, 2':6', 2"-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and 1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu (Ⅰ) or Zn (Ⅱ), are investigated.
A novel compound, (E)-4'-(4-(but-1-en-3-ynyl) phenyl)-2, 2':6', 2"-terpyridine 1 was synthesized from 4'-(4-bromomethylphenyl)-2, 2':6', 2"-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and 1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu (Ⅰ) or Zn (Ⅱ), are investigated.
2007, 18(5): 533-535
doi: 10.1016/j.cclet.2007.03.029
Abstract:
A highly efficient synthesis of 2-amino-N-substituted-benzamides was performed by the condensation of isatoic anhydride with several amines in solvent-free conditions under microwave irradiation. H-Y-zeolites induced heterocyclization of these products with ortho-esters under similar conditions afforded the relevant substituted-quinazolin-4(3H) ones in high yields.
A highly efficient synthesis of 2-amino-N-substituted-benzamides was performed by the condensation of isatoic anhydride with several amines in solvent-free conditions under microwave irradiation. H-Y-zeolites induced heterocyclization of these products with ortho-esters under similar conditions afforded the relevant substituted-quinazolin-4(3H) ones in high yields.
2007, 18(5): 536-538
doi: 10.1016/j.cclet.2007.03.037
Abstract:
2, 3-Dihydro-2-aryl-4(1H)-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc (Otf)3 under mild conditions.
2, 3-Dihydro-2-aryl-4(1H)-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc (Otf)3 under mild conditions.
2007, 18(5): 539-541
doi: 10.1016/j.cclet.2007.03.020
Abstract:
A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, 1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds Ⅰ2, Ⅰ3, Ⅰ4, Ⅰ6, and Ⅰ7 possess more potent NHEl inhibitory activity than cariporide.
A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, 1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds Ⅰ2, Ⅰ3, Ⅰ4, Ⅰ6, and Ⅰ7 possess more potent NHEl inhibitory activity than cariporide.
2007, 18(5): 542-544
doi: 10.1016/j.cclet.2007.03.032
Abstract:
Hydroxylation of 3-nitrotyrosine (3-NT) and 3-NT containing peptide Gly-nitroTyr-Gly in aqueous solution by hydroxyl radical were investigated with gamma irradiation. The structures of the hydroxylated products were confirmed by electrospray ionization mass spectrometry and 1H NMR spectrometry. The reactivity of 3-nitrotyrosine has been investigated using density functional theory (DFr) calculation.
Hydroxylation of 3-nitrotyrosine (3-NT) and 3-NT containing peptide Gly-nitroTyr-Gly in aqueous solution by hydroxyl radical were investigated with gamma irradiation. The structures of the hydroxylated products were confirmed by electrospray ionization mass spectrometry and 1H NMR spectrometry. The reactivity of 3-nitrotyrosine has been investigated using density functional theory (DFr) calculation.
2007, 18(5): 545-547
doi: 10.1016/j.cclet.2007.03.003
Abstract:
Chemical investigation on the ethanol extract from the whole plants of Delphinium chrysotrichum resulted in the isolation of two new diterpene alkaloids named delphatisine A (1) and delphatisine B (2), respectively. The structures of the new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first report on the isolation of diterpenoid alkaloids from the D. Chrysotrichum.
Chemical investigation on the ethanol extract from the whole plants of Delphinium chrysotrichum resulted in the isolation of two new diterpene alkaloids named delphatisine A (1) and delphatisine B (2), respectively. The structures of the new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first report on the isolation of diterpenoid alkaloids from the D. Chrysotrichum.
2007, 18(5): 548-550
doi: 10.1016/j.cclet.2007.03.011
Abstract:
A novel phenylpropanoid glycosides 1, named parispolyside F, and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. Yunnanensis.Their structures were elucidated by spectroscopic methods.
A novel phenylpropanoid glycosides 1, named parispolyside F, and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. Yunnanensis.Their structures were elucidated by spectroscopic methods.
2007, 18(5): 551-553
doi: 10.1016/j.cclet.2007.03.033
Abstract:
Two new phenolic compounds were isolated from whole plant of Artemisia sphaerocephala. The structures were elucidated on the basis of spectroscopic methods as 4-(1-hydroxylethyl)-phenol-1-O-β-D-glucopyranoside and 4-O-acetophenone-β-D-glucopyranosyl-(1-3)-β-D-glucopyranoside.
Two new phenolic compounds were isolated from whole plant of Artemisia sphaerocephala. The structures were elucidated on the basis of spectroscopic methods as 4-(1-hydroxylethyl)-phenol-1-O-β-D-glucopyranoside and 4-O-acetophenone-β-D-glucopyranosyl-(1-3)-β-D-glucopyranoside.
2007, 18(5): 554-556
doi: 10.1016/j.cclet.2007.03.025
Abstract:
Two new saponins named mongholicoside A (1) and mongholicoside B (2) were isolated from the aerial part of Astragalus membranaceus var. mongholicus. Their structures were determined by 1D and 2D NMR, ESI-MS techniques and chemical methods.
Two new saponins named mongholicoside A (1) and mongholicoside B (2) were isolated from the aerial part of Astragalus membranaceus var. mongholicus. Their structures were determined by 1D and 2D NMR, ESI-MS techniques and chemical methods.
2007, 18(5): 557-560
doi: 10.1016/j.cclet.2007.03.016
Abstract:
The electrospray ionization mass spectrometry and tandem mass spectrometry investigation showed that the binding sites of Zn2+ with oxidized insulin B chain are His 5, His 10, and Arg 22, which lead to the selective cleavages of the peptide bonds at Asn 3-Gln 4, His 5-Leu 6, Gly 8-Ser 9, and Glu 21-Arg 22 of oxidized insulin B chain.
The electrospray ionization mass spectrometry and tandem mass spectrometry investigation showed that the binding sites of Zn2+ with oxidized insulin B chain are His 5, His 10, and Arg 22, which lead to the selective cleavages of the peptide bonds at Asn 3-Gln 4, His 5-Leu 6, Gly 8-Ser 9, and Glu 21-Arg 22 of oxidized insulin B chain.
2007, 18(5): 561-564
doi: 10.1016/j.cclet.2007.03.010
Abstract:
Ru (bpy)32+ electrochemiluminescence (ECL) was applied to determination of rutin. ECL intensity of Ru (bpy)32+ could be enhanced in the presence of rutin in basic solution on platinum electrode. At pH 9.9, light emission intensity was found to be linear with rutin in the range of 1-50μmol/L.
Ru (bpy)32+ electrochemiluminescence (ECL) was applied to determination of rutin. ECL intensity of Ru (bpy)32+ could be enhanced in the presence of rutin in basic solution on platinum electrode. At pH 9.9, light emission intensity was found to be linear with rutin in the range of 1-50μmol/L.
2007, 18(5): 565-568
doi: 10.1016/j.cclet.2007.03.026
Abstract:
Correspondence factor analysis (CFA) was employed to study the selectivity of 14 HPLC systems, The tested LC systems were classified as reversed-phase (RP), ion-exchange (IE) and hydrophilic interaction chromatography (HILIC) modes. It was found that the retentions of the hydrophilic solutes on HILIC column were significantly influenced by the second-order effects besides their hydrophilic properties. Organic modifiers and residue silanol groups on silica surface both participated in retention. HypersilTM amino column performed separation in the HILIC mode at appropriate conditions, and its retention mechanism was more similar to that of HILIC silica column than that of HILIC column coating poly (aspartamide) groups.
Correspondence factor analysis (CFA) was employed to study the selectivity of 14 HPLC systems, The tested LC systems were classified as reversed-phase (RP), ion-exchange (IE) and hydrophilic interaction chromatography (HILIC) modes. It was found that the retentions of the hydrophilic solutes on HILIC column were significantly influenced by the second-order effects besides their hydrophilic properties. Organic modifiers and residue silanol groups on silica surface both participated in retention. HypersilTM amino column performed separation in the HILIC mode at appropriate conditions, and its retention mechanism was more similar to that of HILIC silica column than that of HILIC column coating poly (aspartamide) groups.
2007, 18(5): 569-572
doi: 10.1016/j.cclet.2007.03.027
Abstract:
The binding characteristics of neutral red (NR) with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition (SVD) was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6×104 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.
The binding characteristics of neutral red (NR) with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition (SVD) was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6×104 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.
2007, 18(5): 573-576
doi: 10.1016/j.cclet.2007.03.028
Abstract:
A novel terbium complex using 1, 3, 4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices.
A novel terbium complex using 1, 3, 4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices.
2007, 18(5): 577-580
doi: 10.1016/j.cclet.2007.02.016
Abstract:
The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM)) were used to examine the oxidized film's morphology and the structure after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by La-doping and its influence on formation of Cr2O3 film. Laser Raman spectrum was used to examine the tress changes within oxidized films. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 film. The reasons were that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxidized film. Lanthanum mainly existed in the outer surface of Cr2O3 film in the forms of fine La2O3 and LaCrO3 spinel particles.
The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM)) were used to examine the oxidized film's morphology and the structure after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by La-doping and its influence on formation of Cr2O3 film. Laser Raman spectrum was used to examine the tress changes within oxidized films. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 film. The reasons were that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxidized film. Lanthanum mainly existed in the outer surface of Cr2O3 film in the forms of fine La2O3 and LaCrO3 spinel particles.
2007, 18(5): 581-584
doi: 10.1016/j.cclet.2007.03.034
Abstract:
Europium ions were chemically bound to CdS nanoparticles surface by diethylenetri-aminepentaacetate (DTPA, 1) in a two-step synthetic route. First 1 was applied to chelate with cadmium on the surface of cadmium-rich CdS nanoparticles and act as a capping agent. Further, the purified 1-capped particles were used to bind with Eu3+. The purified and redispersed particles were characterized by photoluminescence spectroscopy, TEM and SEM. It was observed that Eu3+ on the nanoparticle surface significantly increased the band gap emission and decreased the surface emission intensity of the CdS nanoparticles.
Europium ions were chemically bound to CdS nanoparticles surface by diethylenetri-aminepentaacetate (DTPA, 1) in a two-step synthetic route. First 1 was applied to chelate with cadmium on the surface of cadmium-rich CdS nanoparticles and act as a capping agent. Further, the purified 1-capped particles were used to bind with Eu3+. The purified and redispersed particles were characterized by photoluminescence spectroscopy, TEM and SEM. It was observed that Eu3+ on the nanoparticle surface significantly increased the band gap emission and decreased the surface emission intensity of the CdS nanoparticles.
2007, 18(5): 585-587
doi: 10.1016/j.cclet.2007.03.006
Abstract:
Some Mo-V-Te-La catalysts with varied component were prepared by hydrothermal synthesis and dried with microwave method. The component of the catalyst were greatly affected the crystal structure and Raman spectrum. The phase in the catalysts was different when the Mo, V, and Te content varied. When the catalyst containing the same Mo, V content, due to the effect of dopant of Te element (V0.07Mo0.93)5O14 became the main phase in the catalyst. The catalyst also showed good activity for the reaction of selective oxidation propane to acrolein and acrylic acid.
Some Mo-V-Te-La catalysts with varied component were prepared by hydrothermal synthesis and dried with microwave method. The component of the catalyst were greatly affected the crystal structure and Raman spectrum. The phase in the catalysts was different when the Mo, V, and Te content varied. When the catalyst containing the same Mo, V content, due to the effect of dopant of Te element (V0.07Mo0.93)5O14 became the main phase in the catalyst. The catalyst also showed good activity for the reaction of selective oxidation propane to acrolein and acrylic acid.
2007, 18(5): 588-590
doi: 10.1016/j.cclet.2007.03.036
Abstract:
A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results. Demonstrated that the novel fibrous hypercrosslinked sorbent has narrow pore-size distribution, small average porous radius (1.90 nm), high specific surface area (362.31 m2/g), and fine sorptive properties for small organic molecules.
A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results. Demonstrated that the novel fibrous hypercrosslinked sorbent has narrow pore-size distribution, small average porous radius (1.90 nm), high specific surface area (362.31 m2/g), and fine sorptive properties for small organic molecules.
2007, 18(5): 591-594
doi: 10.1016/j.cclet.2007.03.021
Abstract:
Silylated Ti-grafted hexagonal mesoporous silica (HMS) catalyst was prepared by the chemical vapor deposition (CVD) using TiCl4 as titanium source and hexamethyldisilazane (HMDSZ) as silylating agent. The samples were characterized by XRD, N2-adsorption, FTIR, 29Si NMR, DR UV-vis, and evaluated by epoxidation of styrene, propylene, cyclohexene, and 1-hexene with cumene hydroperoxide (CHP) as oxidant, respectively. It is revealed that the catalyst possesses typical mesoporous structure, high hydrophobicity and highly dispersed tetracoordinated titanium sites and hence exhibits excellent performance in epoxidation of olefins.
Silylated Ti-grafted hexagonal mesoporous silica (HMS) catalyst was prepared by the chemical vapor deposition (CVD) using TiCl4 as titanium source and hexamethyldisilazane (HMDSZ) as silylating agent. The samples were characterized by XRD, N2-adsorption, FTIR, 29Si NMR, DR UV-vis, and evaluated by epoxidation of styrene, propylene, cyclohexene, and 1-hexene with cumene hydroperoxide (CHP) as oxidant, respectively. It is revealed that the catalyst possesses typical mesoporous structure, high hydrophobicity and highly dispersed tetracoordinated titanium sites and hence exhibits excellent performance in epoxidation of olefins.
2007, 18(5): 595-597
doi: 10.1016/j.cclet.2007.03.030
Abstract:
A series of novel poly (aryl ether nitrile) s containing phthalazinone moiety were synthesized by the nucleophilic displacement reaction of bisphenol-like monomers (Ⅰ) with 2, 6-difluorobenzonitrile. The inherent viscosities ranged from 0.46 to 1.07 dL g-1.The glass transition temperatures were in the range of 277-295℃, and the temperatures for 10% weight loss in nitrogen atmosphere were found between 495 and 527℃. The structures of these resultant polymers were confirmed by FT-IR and 1H NMR. Moreover, the properties of poly (aryl ether nitrile) s including solubility and crystallinity were also studied.
A series of novel poly (aryl ether nitrile) s containing phthalazinone moiety were synthesized by the nucleophilic displacement reaction of bisphenol-like monomers (Ⅰ) with 2, 6-difluorobenzonitrile. The inherent viscosities ranged from 0.46 to 1.07 dL g-1.The glass transition temperatures were in the range of 277-295℃, and the temperatures for 10% weight loss in nitrogen atmosphere were found between 495 and 527℃. The structures of these resultant polymers were confirmed by FT-IR and 1H NMR. Moreover, the properties of poly (aryl ether nitrile) s including solubility and crystallinity were also studied.
2007, 18(5): 598-600
doi: 10.1016/j.cclet.2007.03.024
Abstract:
A novel phthalazinone modified epoxy acrylate resin for the high temperature resistant ultravioet (UV) curable coating was synthesized. The methacrylated epoxy resins obtained were utilized to UV radiation curing by taking 2.5% (wt%) of photoinitiator in combination with 20% (wt%) of diluent, and generated the interpenetraring polymer networks. The cured film had good thermal and chemical stability.
A novel phthalazinone modified epoxy acrylate resin for the high temperature resistant ultravioet (UV) curable coating was synthesized. The methacrylated epoxy resins obtained were utilized to UV radiation curing by taking 2.5% (wt%) of photoinitiator in combination with 20% (wt%) of diluent, and generated the interpenetraring polymer networks. The cured film had good thermal and chemical stability.
2007, 18(5): 601-604
doi: 10.1016/j.cclet.2007.03.014
Abstract:
Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system was investigated at 50℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim] [CH3COO]), 1-methylimidazolium propionate ([mim] [CH3CH2COO]) and 1-methylimidazolium butyrate ([mim] [CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim] [CH3COO]) >kapp([mim] [CH3CH2COO]) >kapp([mim] [CH3CH2CH2COO]).
Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system was investigated at 50℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim] [CH3COO]), 1-methylimidazolium propionate ([mim] [CH3CH2COO]) and 1-methylimidazolium butyrate ([mim] [CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim] [CH3COO]) >kapp([mim] [CH3CH2COO]) >kapp([mim] [CH3CH2CH2COO]).
2007, 18(5): 605-608
doi: 10.1016/j.cclet.2007.03.007
Abstract:
A novel biodegradable polymer-poly (ethene maleic acid ester-co-D, L-lactide acid) was synthesized by copolymerizing lactide and prepolymer, which was prepared by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst, attempting to improve the hydrophilicity, increase flexibility and modulate the degradation rate. FTIR, 1H NMR, MALLS and DSC were employed to characterize these polymers.
A novel biodegradable polymer-poly (ethene maleic acid ester-co-D, L-lactide acid) was synthesized by copolymerizing lactide and prepolymer, which was prepared by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst, attempting to improve the hydrophilicity, increase flexibility and modulate the degradation rate. FTIR, 1H NMR, MALLS and DSC were employed to characterize these polymers.
2007, 18(5): 609-612
doi: 10.1016/j.cclet.2007.03.031
Abstract:
Sulfonated poly (phthalazinone) s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidic compounds, and polyetherimide (PEI) as the basic compounds, casting from their N-methylpyrrolidone (NMP) solution directly onto clean glass plates at 60℃ aiming at enhancing membrane toughness and other relative properties. The resulted acid-base composite membranes had excellent resistance to swelling, thermo-stability, hydrolysis resistance and oxidative resistance properties with highly ion-exchange capacity (IEC).
Sulfonated poly (phthalazinone) s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidic compounds, and polyetherimide (PEI) as the basic compounds, casting from their N-methylpyrrolidone (NMP) solution directly onto clean glass plates at 60℃ aiming at enhancing membrane toughness and other relative properties. The resulted acid-base composite membranes had excellent resistance to swelling, thermo-stability, hydrolysis resistance and oxidative resistance properties with highly ion-exchange capacity (IEC).
2007, 18(5): 613-616
doi: 10.1016/j.cclet.2007.03.015
Abstract:
The novel biodegradable copolymer PDLLA-(MAH-Diol)n-PDLLA with unsaturated bond was synthesized by copolymerizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly (ethylene glycol), using p-toluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.
The novel biodegradable copolymer PDLLA-(MAH-Diol)n-PDLLA with unsaturated bond was synthesized by copolymerizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly (ethylene glycol), using p-toluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.
2007, 18(5): 617-620
doi: 10.1016/j.cclet.2007.03.023
Abstract:
A simple method has been developed to prepare cuprous selenide nanocrystals by the reaction of copper nitrate trihydrate with selenium and sodium mercaptoacetate in aqueous ammonia system. Cu2 Se nanocrystals were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), electron diffraction (ED), fluorescence spectrum and ultraviolet-visible absorption spectrum. Cu2 Se nanocrystals showed berzelianite structure with 20-40 nm in length and 10-20 nm in width. A possible mechanism is also discussed.
A simple method has been developed to prepare cuprous selenide nanocrystals by the reaction of copper nitrate trihydrate with selenium and sodium mercaptoacetate in aqueous ammonia system. Cu2 Se nanocrystals were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), electron diffraction (ED), fluorescence spectrum and ultraviolet-visible absorption spectrum. Cu2 Se nanocrystals showed berzelianite structure with 20-40 nm in length and 10-20 nm in width. A possible mechanism is also discussed.
2007, 18(5): 621-624
doi: 10.1016/j.cclet.2007.02.017
Abstract:
A quantitative structure-activity relationships (QSAR) study is suggested for the prediction of solubility of some thiazolidine-4-carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors including electrostatic potentials and local charges at each atom, HOMO and LUMO energies, etc. Modeling of the solubility of thiazolidine4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares (PLS). The subset of descriptors, which resulted in the low prediction error, was selected by genetic algorithm. This model was applied for the prediction of the solubility of some thiazolidine-4-carboxylic acid derivatives, which were not in the modeling procedure. The relative errors of prediction lower that -4% was obtained by using GA-PLS method. The resulted model showed high prediction ability with RMSEP of 3.8836 and 2.9500 for PLS and GA-PLS models, respectively.
A quantitative structure-activity relationships (QSAR) study is suggested for the prediction of solubility of some thiazolidine-4-carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors including electrostatic potentials and local charges at each atom, HOMO and LUMO energies, etc. Modeling of the solubility of thiazolidine4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares (PLS). The subset of descriptors, which resulted in the low prediction error, was selected by genetic algorithm. This model was applied for the prediction of the solubility of some thiazolidine-4-carboxylic acid derivatives, which were not in the modeling procedure. The relative errors of prediction lower that -4% was obtained by using GA-PLS method. The resulted model showed high prediction ability with RMSEP of 3.8836 and 2.9500 for PLS and GA-PLS models, respectively.
