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在动量空间中观察二氧甲基甲烷的端基异构效应

发表时间:2008-04-15  浏览量:1627  下载量:691
全部作者: 黄艳茹,宁传刚,张书锋,刘昆,罗志弘,邓景康
作者单位: 清华大学物理系原子分子纳米科学教育部重点实验室
摘 要: 首次利用改进后的具有高分辨率的第三代电子动量谱仪,在动量空间中从轨道层次上研究二氧甲基甲烷分子G+G+构像的端基异构效应。二氧甲基甲烷G+G+构像轨道电离能的实验数据和HF,DFT/B3LYP,ADC(3)的理论计算结果显示出沿着C-O-C-O-C结构链由端基异构形成的轨道之间通过空间和通过键相互作用使轨道10a更加稳定,表现为10a轨道电离能比邻近的轨道9b高约1.6 eV,在HeI光电子谱上表现为两个轨道之间有较大的能量间隔;比较DFT和单粒子格林函数ADC(3)方法在不同基组下轨道动量谱的理论计算结果说明只有在基组中包含弥散函数,才能正确地描述轨道动量谱在低动量区域的实验数据,即由端基异构效应引起的轨道离域性。
关 键 词: 电子动量谱学;端基异构效应;单粒子格林函数ADC(3);二氧甲基甲烷
Title: Investigation into anomeric effect of dimethoxymethane in momentum space
Author: HUANG Yanru, NING Chuangang, ZHANG Shufeng, LIU Kun, LUO Zhihong, Deng Jingkang
Organization: Key Laboratory of Atom and molecular Nanosciences of MOE, Department of Physics, Tsinghua University
Abstract: Anomeric effect of G+G+ conformer of dimethoxymethane was firstly investigated in momentum space using the improved 3rd generation electron momentum spectrometer. The experimental data and theoretical results obtained from HF, DFT/B3LYP and ADC(3) calculations for its G+G+ conformation display that along C-O-C-O-C backbone through-orbital and through-space electronic interactions caused by anomeric effect localizes orbital 10a, That is to say, its ionization energy is higher about 1.6 eV than one of close orbital 9b, corresponding it is observed that there is a wide gap between two peaks relative with these orbitals from HeI photoelectron spectroscopy. A comparison of DFT calculations upon spherically averaged (e, 2e) electron momentum distributions with 1p-GF/ADC(3) ones shows that it is essential that inclusion of diffuse functions in employed various basis sets to correctly describe the experimental results for momentum profile and enables us to identify specific fingerprints of through-space orbital interactions associated with the anomeric effect.
Key words: electron momentum spectroscopy; anomeric effect; 1p-GF/ADC(3); dimethoxymethane
发表期数: 2008年8月第7期
引用格式: 黄艳茹,宁传刚,张书锋,等. 在动量空间中观察二氧甲基甲烷的端基异构效应[J]. 中国科技论文在线精品论文,2008,1(7):753-758.
 
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