检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
机构地区:[1]陇东学院化学化工学院,甘肃省庆阳市西峰区兰州路745000 [2]陇东学院科技处,甘肃省庆阳745000
出 处:《光谱实验室》2012年第1期232-235,共4页Chinese Journal of Spectroscopy Laboratory
摘 要:化学位移是核磁共振技术的重要参数,目前对~1H NMR、^(13)C NMR已提出一系列估算化学位移的经验公式,但^(19)F NMR化学位移规律研究报道则较少,以δ=B+∑△i+C化学位移通式为基础,分析屏蔽常数对化学位移的作用,并针对^(19)F原子,分析了氟的电子云密度、立体效应、溶剂效应、氢键、标准、浓度和温度等影响因素,对^(19)F NMR化学位移经验公式的提出提供理论依据。Chemical shift is an important parameter in nuclear magnetic resonance technology. Currently,a series of empirical formulas for estimating chemical shift were reported on^1H NMR, ^(13)C NMR,but that on ^(19)F NMR were less.On the basis of the formula:δ= B+Σ△i+C,the effect of the screening constant on chemical shift was analyzed.Aimed at ^(19)F atom,the effects of the electron cloud density,the stereo effect,the solvent effect,the hydrogen bond,the standard,concentration and the temperature of fluorine were analyzed.The method provides theoretical basis for the empirical formulas of ^(19)F NMR chemical shift.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:18.188.148.202