核磁共振化学位移的态叠加微扰INDO/σ计算方法

本文提出一套在态叠加微扰理论基础上的INDO近似计算方法,把化学位移的计算推广到包含d和f轨道的一般情况。 NMR化学位移计算方法 应用量子力学态叠加微扰理论,可将分子中原子N的磁共振参数σN分成反磁贡献σNd,顺磁贡献σNp,原子M对N产生的贡献σNM以及环流效应σNring.

π电子总能量E_(π)与走步数S_(2l)的关系

本文推导并分析了几类共轭烃的闭走步数公式及其内在联系,得到了HMO E_(n)展开系数应满足的一些条件,提出了一种估算E_(n)的新方法。π电子总能量E_(π)是共轭分子基态稳定性或反应活性的主要判据之一。除通过分子轨道能级来计算外,人们还常常寻求各种方法直接求算E_(π)值^([1-5])。

CaO对ZSM-5沸石选择性催化作用的影响

为了进一步闸明ZSM-5沸石的选择性催化作用,本文利用CaO对其改性,从实验和理论计算方面探讨对二甲苯选择性的变化,得到一些有意义的结果。(一)实验及结果ZSM-5沸石原粉,经HCl交换成HZSM-5沸石,再和CaO按一定比例混合在一定温度下焙烧数小时,即为改性的催化剂HZSM-5-CaO。

PROBLEM ON SPECTRA OF CONJUGATE MOLECULES HAVING REPEATED UNITS

Problem on spectra of conjugate molecules having repeated units have been discussed before. However, most of these discussions are confined to molecules that have only single bond between adjacent repeated units. In this paper, the results of a previous paper are extended to include the case of straight chain conjugate

THE ELECTRONIC CONFIGURATION OF 5-MEMBERED AND 6-MEMBERED RING SANDWICHES

In this paper, a method of local symmetry is applied to metallo-organic 5-membered and 6-membered ring poly-decker sandwiches (briefly called 5-membered sandwich Ⅰ and 6-membered sandwich Ⅱ), and the nature of their chemical bond is discussed by means of the HMO theory. The stable electronic configuration for these sandwiches is obtained. A working rule for the total number of valence electrons being 6(2n+l)+4t is proposed. It is reasonable to suggest some potential synthetic goals of poly-decker sandwiches. The discovery in 1951 of the transition metal π-complex, ferrocene, created a new research field of metalloorganic sandwiches. Since then, a lot of bis-decker sandwich-