HeI photoelectron spectra of w-heterocycle a-cyano polyenic ethyl ester compounds (1-6) have been given in this paper. Assignment of the spectra is also done with the aid of HeI photoelectron spectroscopic (PES) resul...HeI photoelectron spectra of w-heterocycle a-cyano polyenic ethyl ester compounds (1-6) have been given in this paper. Assignment of the spectra is also done with the aid of HeI photoelectron spectroscopic (PES) results of smaller molecules which have similar atomic group to the molecules studied, and the aid of MNDO molecules orbital calculations. The lowest PES experimental ionization potentials (IPs in eV) of different molecules reduce gradually with the increasing number of ethylenic group. The -CO2C2H5 group can be only considered as a substituent.展开更多
Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） me...Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） method at the B3LYP/6-31G＊ level. Based on the quantum-chemical calculation results and the Pearson coefficients between FA and quantum- chemical parameters, V, LogP, MR and EHOMO are shown to be the important relative factors which affect FA of the title compounds.展开更多
Ni–Ga alloy(Ni/Ga atomic ratio of 8),Ni3Ga and Ni5Ga3 intermetallic compounds(IMCs)catalysts were prepared from Ni–Mg-Al-Ga layered double hydroxides(LDHs)for the deoxygenation of methyl esters to hydrocarbons.In th...Ni–Ga alloy(Ni/Ga atomic ratio of 8),Ni3Ga and Ni5Ga3 intermetallic compounds(IMCs)catalysts were prepared from Ni–Mg-Al-Ga layered double hydroxides(LDHs)for the deoxygenation of methyl esters to hydrocarbons.In the alloy and IMCs,the presence of Ga reduced the surface Ni atom density,and the charge transfer from Ga to Ni increased the electron density of Ni.In the deoxygenation of methyl laurate,the Ni catalyst gave a complete hydrogenolysis of methyl laurate to CH4at 330°C and 3.0 MPa,while the presence of Ga promoted the HDO pathway and suppressed C–C bond hydrogenolysis and methanation.The Ni5Ga3 catalyst exhibited the best desired performance.Even at 400°C,it gave the yield of C11 and C12 hydrocarbons of ~99%,and the selectivity to CH4(SCH4) was only 2.4%.In the deoxygenation of methyl octanoate and methyl palmitate,the Ni5Ga3 catalyst also gave the yield of hydrocarbons above95%.Reactivity evaluation and methyl propionate-TPD and TPSR results indicate that the C–OCH3 bond instead of the O–CH3 one was cleaved on both Ni and bimetallic Ni–Ga catalysts.It is highlighted that methanol,derived from the C–OCH3 bond hydrogenolysis,mainly decomposed to CO and H2 on IMCs,while it was converted to methane on metallic Ni and alloy.It is of great significance that H2 could be yielded from the methyl ester itself.In short,the utilization of Ni–Ga IMCs can effectively reduce carbon loss and H2 consumption,all of which are ascribed to the geometric and electronic effects of Ga.展开更多
为优化分散液液微萃取(dispersive liquid-liquid microextraction,DLLME)测定葡萄酒中酯类化合物的方法,以模拟葡萄酒为试材,研究分散剂种类及体积、萃取剂种类及体积、样品体积、盐添加质量及萃取时间7个因素对模拟葡萄酒中16种酯类...为优化分散液液微萃取(dispersive liquid-liquid microextraction,DLLME)测定葡萄酒中酯类化合物的方法,以模拟葡萄酒为试材,研究分散剂种类及体积、萃取剂种类及体积、样品体积、盐添加质量及萃取时间7个因素对模拟葡萄酒中16种酯类化合物萃取效果的影响,结合单因素和Box-Behnken响应面试验对萃取条件进行优化,并采用气相色谱-质谱(GC-MS)进行定性定量分析。结果表明,模拟葡萄酒中酯类化合物的最佳萃取条件为:分散剂甲醇1200μL,萃取剂二氯甲烷600μL,样品体积7 mL,不添加盐,萃取时间1.0min。在此条件下,16种待测酯类化合物的线性关系良好,R2均高于0.995,检测限(limit of detection,LOD)和定量限(limit of quantitation,LOQ)分别为0.004~0.078 mg/L和0.012~0.261 mg/L;3个质量浓度水平的加标回收率为83.3%~111.3%,日内和日间相对标准偏差(relative standard deviation,RSD)为0.02%~7.69%。对2018—2020年的‘黑比诺’干红葡萄酒和‘贵人香’冰白葡萄酒样品测定时,该方法表现出良好的应用效果,并印证了酯类化合物的种类和质量浓度变化与酒样类型及陈酿年份密切相关。该研究可为深入研究葡萄酒中酯类化合物的代谢提供依据。展开更多
【目的】探明不同产地八角果实挥发性代谢物组分,为八角种质资源评价、优质原料选材提供参考。【方法】以云南(西畴县、广南县、马关县、麻栗坡县)和广西(崇左市、钦州市)八角果实为材料,采用全自动顶空固相微萃取(HS-SPME)和气质联用(G...【目的】探明不同产地八角果实挥发性代谢物组分,为八角种质资源评价、优质原料选材提供参考。【方法】以云南(西畴县、广南县、马关县、麻栗坡县)和广西(崇左市、钦州市)八角果实为材料,采用全自动顶空固相微萃取(HS-SPME)和气质联用(GC-MS)技术,广泛靶向检测各产地八角果实挥发性代谢物,并通过主成分和正交偏最小二乘法分析挥发性代谢物成分。【结果】八角果实挥发性代谢物含量以萜类、酯类和杂环化合物相对较高,分别占果实总挥发性代谢物的31%、14%和11%。不同产地八角果实挥发性代谢物成分存在明显差异,差异代谢物共有212~511个,其中,萜类物质含量最高,其次为杂环化合物和酮类物质。广南县和崇左市八角果实差异代谢物最多,为511个,其中,上调和下调具有代表性的10个差异代谢物中,酯类物质最多,其次是萜类和醇类。KEGG注释表明广南县八角果实单萜生物合成途径(Monoterpenoid biosynthesis)明显上调,倍半萜和三萜生物合成途径(Sesquiterpenoid and triterpenoid biosynthesis)、泛醌和其他萜类醌生物合成途径(Ubiquinone and other terpenoid-quinone biosynthesis)明显下调。【结论】八角果实挥发性代谢物主要为萜类、酯类和杂环化合物。6个不同产地八角果实挥发性代谢物呈现一定差异,差异代谢物以萜类为主,其次为杂环化合物和酮类物质,可作为评价和筛选香料和药用八角种质资源的依据。展开更多
The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation perform...The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.展开更多
A new series of Schiff base esters, 4-（dimethylamino）benzylidene-4＇-alkanoyloxyanilines containing even number of carbons at the end group of the molecules （Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18） were synthe...A new series of Schiff base esters, 4-（dimethylamino）benzylidene-4＇-alkanoyloxyanilines containing even number of carbons at the end group of the molecules （Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18） were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties. C 2009 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘HeI photoelectron spectra of w-heterocycle a-cyano polyenic ethyl ester compounds (1-6) have been given in this paper. Assignment of the spectra is also done with the aid of HeI photoelectron spectroscopic (PES) results of smaller molecules which have similar atomic group to the molecules studied, and the aid of MNDO molecules orbital calculations. The lowest PES experimental ionization potentials (IPs in eV) of different molecules reduce gradually with the increasing number of ethylenic group. The -CO2C2H5 group can be only considered as a substituent.
基金talents in University (NCET-04-0649) the Natural Science Foundation of Shandong Province (Y2006B07,Z2006B01)
文摘Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） method at the B3LYP/6-31G＊ level. Based on the quantum-chemical calculation results and the Pearson coefficients between FA and quantum- chemical parameters, V, LogP, MR and EHOMO are shown to be the important relative factors which affect FA of the title compounds.
基金support from the National Natural Science Foundation of China(Nos.21576193 and 21176177)。
文摘Ni–Ga alloy(Ni/Ga atomic ratio of 8),Ni3Ga and Ni5Ga3 intermetallic compounds(IMCs)catalysts were prepared from Ni–Mg-Al-Ga layered double hydroxides(LDHs)for the deoxygenation of methyl esters to hydrocarbons.In the alloy and IMCs,the presence of Ga reduced the surface Ni atom density,and the charge transfer from Ga to Ni increased the electron density of Ni.In the deoxygenation of methyl laurate,the Ni catalyst gave a complete hydrogenolysis of methyl laurate to CH4at 330°C and 3.0 MPa,while the presence of Ga promoted the HDO pathway and suppressed C–C bond hydrogenolysis and methanation.The Ni5Ga3 catalyst exhibited the best desired performance.Even at 400°C,it gave the yield of C11 and C12 hydrocarbons of ~99%,and the selectivity to CH4(SCH4) was only 2.4%.In the deoxygenation of methyl octanoate and methyl palmitate,the Ni5Ga3 catalyst also gave the yield of hydrocarbons above95%.Reactivity evaluation and methyl propionate-TPD and TPSR results indicate that the C–OCH3 bond instead of the O–CH3 one was cleaved on both Ni and bimetallic Ni–Ga catalysts.It is highlighted that methanol,derived from the C–OCH3 bond hydrogenolysis,mainly decomposed to CO and H2 on IMCs,while it was converted to methane on metallic Ni and alloy.It is of great significance that H2 could be yielded from the methyl ester itself.In short,the utilization of Ni–Ga IMCs can effectively reduce carbon loss and H2 consumption,all of which are ascribed to the geometric and electronic effects of Ga.
文摘为优化分散液液微萃取(dispersive liquid-liquid microextraction,DLLME)测定葡萄酒中酯类化合物的方法,以模拟葡萄酒为试材,研究分散剂种类及体积、萃取剂种类及体积、样品体积、盐添加质量及萃取时间7个因素对模拟葡萄酒中16种酯类化合物萃取效果的影响,结合单因素和Box-Behnken响应面试验对萃取条件进行优化,并采用气相色谱-质谱(GC-MS)进行定性定量分析。结果表明,模拟葡萄酒中酯类化合物的最佳萃取条件为:分散剂甲醇1200μL,萃取剂二氯甲烷600μL,样品体积7 mL,不添加盐,萃取时间1.0min。在此条件下,16种待测酯类化合物的线性关系良好,R2均高于0.995,检测限(limit of detection,LOD)和定量限(limit of quantitation,LOQ)分别为0.004~0.078 mg/L和0.012~0.261 mg/L;3个质量浓度水平的加标回收率为83.3%~111.3%,日内和日间相对标准偏差(relative standard deviation,RSD)为0.02%~7.69%。对2018—2020年的‘黑比诺’干红葡萄酒和‘贵人香’冰白葡萄酒样品测定时,该方法表现出良好的应用效果,并印证了酯类化合物的种类和质量浓度变化与酒样类型及陈酿年份密切相关。该研究可为深入研究葡萄酒中酯类化合物的代谢提供依据。
文摘【目的】探明不同产地八角果实挥发性代谢物组分,为八角种质资源评价、优质原料选材提供参考。【方法】以云南(西畴县、广南县、马关县、麻栗坡县)和广西(崇左市、钦州市)八角果实为材料,采用全自动顶空固相微萃取(HS-SPME)和气质联用(GC-MS)技术,广泛靶向检测各产地八角果实挥发性代谢物,并通过主成分和正交偏最小二乘法分析挥发性代谢物成分。【结果】八角果实挥发性代谢物含量以萜类、酯类和杂环化合物相对较高,分别占果实总挥发性代谢物的31%、14%和11%。不同产地八角果实挥发性代谢物成分存在明显差异,差异代谢物共有212~511个,其中,萜类物质含量最高,其次为杂环化合物和酮类物质。广南县和崇左市八角果实差异代谢物最多,为511个,其中,上调和下调具有代表性的10个差异代谢物中,酯类物质最多,其次是萜类和醇类。KEGG注释表明广南县八角果实单萜生物合成途径(Monoterpenoid biosynthesis)明显上调,倍半萜和三萜生物合成途径(Sesquiterpenoid and triterpenoid biosynthesis)、泛醌和其他萜类醌生物合成途径(Ubiquinone and other terpenoid-quinone biosynthesis)明显下调。【结论】八角果实挥发性代谢物主要为萜类、酯类和杂环化合物。6个不同产地八角果实挥发性代谢物呈现一定差异,差异代谢物以萜类为主,其次为杂环化合物和酮类物质,可作为评价和筛选香料和药用八角种质资源的依据。
基金supported by the Natural Science Foundation of Guizhou Province(QKJ[2014]2140 and QJTD[2012]052)
文摘The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.
基金Universiti Tunku Abdul Rahman(UTAR) for the research facilities andfinancial support through UTAR Vote No.6202/O05Universiti Sains Malaysia for the use of its research facilities.
文摘A new series of Schiff base esters, 4-（dimethylamino）benzylidene-4＇-alkanoyloxyanilines containing even number of carbons at the end group of the molecules （Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18） were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties. C 2009 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
