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多光子电离下醇类团簇中的反应
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作者 蔡廷栋 张树东 +2 位作者 孔祥和 许明坤 姜素蓉 《光谱实验室》 CAS CSCD 2006年第3期561-565,共5页
应用NdYAG(Spectra-PhysicsLAB-170)脉冲激光器输出的355nm紫外激光实现了对甲醇、乙醇及正丙醇的多光子电离,对每一种样品通过质谱技术都观测到了两个质子化团簇离子系列(R1,2,3OH)nH+和(R1,2,3OH)n(H2O)H+(R1,2,3代表CH3、CH3CH2及CH3... 应用NdYAG(Spectra-PhysicsLAB-170)脉冲激光器输出的355nm紫外激光实现了对甲醇、乙醇及正丙醇的多光子电离,对每一种样品通过质谱技术都观测到了两个质子化团簇离子系列(R1,2,3OH)nH+和(R1,2,3OH)n(H2O)H+(R1,2,3代表CH3、CH3CH2及CH3CH2CH2),结合在HF/STO-3G和B3LYP/6-31G++水平上的从头计算对其反应通道做了分析,发现其产生经过了团簇内部的质子转移反应及离子-分子反应,且质子主要来自于羟基上的氢离子。并结合从头算分析了(R1,2,3OH)nH+的结构,给出了幻数团簇(R1,2,3OH)3H+的构型。同时对(R1,2,3)n(H2O)H+系列只在n值较大时出现做了相应的解释。 展开更多
关键词 质子化离子 质子转移 溶剂化 从头计算
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三元甲醇辅助质子转移的动力学旁证:硝基联苯酚激发三重态的瞬态吸收研究
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作者 潘星行 龙静 +2 位作者 杜勇 郑旭明 薛佳丹 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2023年第1期50-56,I0008-I0012,I0001,I0002,共14页
羟基芳烃化合物是一种典型“光酸”,在催化合成和生物过程中具有广泛应用、由于激发单重态寿命较短,大多数具有中等激发态酸度的羟基芳烃化合物无法在非水溶剂(如醇)中解离.硝基联苯酚中的硝基可增加激发单重态和三重态间的自旋轨道耦合... 羟基芳烃化合物是一种典型“光酸”,在催化合成和生物过程中具有广泛应用、由于激发单重态寿命较短,大多数具有中等激发态酸度的羟基芳烃化合物无法在非水溶剂(如醇)中解离.硝基联苯酚中的硝基可增加激发单重态和三重态间的自旋轨道耦合,通过超快的系间窜越产生最低激发三重态,且具有较高量子产率.本文利用瞬态吸收光谱和动力学分析发现:尽管三重态硝基联苯酚具有中等酸性,但由于其寿命较长,能够与甲醇发生质子转移反应,三重态硝基联苯酚连.续与三个甲醇分子反应形成氢键复合物是质子转移的决速步骤.这--发现表明,具有较长激发态寿命的光酸可以通过具有足够碱性的醇类低聚物诱导其解离. 展开更多
关键词 硝基联苯酚 激发态质子转移 醇团簇 布朗斯特碱 瞬态吸收
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Highly dispersed Cd cluster supported on TiO_(2) as an efficient catalyst for CO_(2) hydrogenation to methanol 被引量:6
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作者 Jijie Wang Jittima Meeprasert +8 位作者 Zhe Han Huan Wang Zhendong Feng Chizhou Tang Feng Sha Shan Tang Guanna Li Evgeny A.Pidko Can Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第3期761-770,共10页
The conversion of CO_(2) to methanol with high activity and high selectivity remains challenging owing to the kinetic and thermodynamic limitations associated with the low chemical reactivity exhibited by CO_(2).Herei... The conversion of CO_(2) to methanol with high activity and high selectivity remains challenging owing to the kinetic and thermodynamic limitations associated with the low chemical reactivity exhibited by CO_(2).Herein,we report a novel Cd/TiO_(2) catalyst exhibiting a methanol selectivity of 81%,a CO_(2) conversion of 15.8%,and a CH_(4) selectivity below 0.7%.A combination of experimental and computational studies revealed that the unique electronic properties exhibited by the Cd clusters supported by the TiO_(2) matrix were responsible for the high selectivity of CO_(2) hydrogenation to methanol via the HCOO*pathway at the interfacial catalytic sites. 展开更多
关键词 CO_(2)hydrogenation METHANOL Cd/TiO_(2)catalyst Cd cluster TiO_(2)
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Producing of cinnamyl alcohol from cinnamaldehyde over supported gold nanocatalyst 被引量:1
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作者 Yuan Tan Xiaoyan Liu +3 位作者 Leilei Zhang Fei Liu Aiqin Wang Tao Zhang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第3期470-481,共12页
Chemoselective hydrogenation of unsaturated aldehyde to unsaturated alcohol has attracted growing interests in recent years due to its widespread applications in fine chemicals.However,the hydrogenation of the C=O bon... Chemoselective hydrogenation of unsaturated aldehyde to unsaturated alcohol has attracted growing interests in recent years due to its widespread applications in fine chemicals.However,the hydrogenation of the C=O bond was thermodynamically and kinetically unfavorable over the hydrogenation of the C=C bond.Thus,to obtain the unsaturated alcohol from the unsaturated aldehyde is very difficult in most of the catalytic systems.In this work,ZnAl-hydrotalcite-supported cysteine-capped Au25 nanoclusters were used as the precatalysts for chemoselective hydrogenation of cinnamaldehyde to cinnamyl alcohol.The catalyst showed stable high selectivity(~95%)at prolonged reaction time and complete conversion of the substrate.According to the results of the control experiments,the in-situ DRIFTS of the substrate under high pressure of hydrogen and the 27Al MAS-NMR spectroscopy,we proposed that the difference of the preferential adsorption of the C=O bond to that of the C=C bond was derived from the nature of the support of the gold catalysts. 展开更多
关键词 Gold nanocluster Support effect Cinnamyl alcohol Selective hydrogenation CINNAMALDEHYDE
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Hydrothermal Synthesis and Crystal Structure of [H_4As_8V_(14)O_(42)(H_2O)]·6H_2O
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作者 崔小兵 徐吉庆 +3 位作者 李光华 施展 丁红 杨国昱 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第10期1138-1142,共5页
The title compound [H4As8V14O42(H2O)]6H2O 1 has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. It crystallizes in trigonal, space group R3c with a = b = 36... The title compound [H4As8V14O42(H2O)]6H2O 1 has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. It crystallizes in trigonal, space group R3c with a = b = 36.447(6), c = 21.485(5) ? V = 24717(8) 3, Z = 18, Mr = 2114.66, Dc = 2.557g/cm3, F(000) = 17928, m = 7.149 mm-1, R = 0.0792 and wR = 0.1265. The [H4As8V14O42- (H2O)] cluster consists of fourteen VO5 square pyramids linked by four As2O5 handle-like units. 展开更多
关键词 hydrothermal synthesis POLYOXOMETALATE arsenic-vanadium cluster hydrogen bond crystal structure
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