RING STRAIN IN CYCLOPROPANE, CYCLOPROPENE, SILACYCLOPROPANE, AND SILACYCLOPROPENE
RING STRAIN IN CYCLOPROPANE, CYCLOPROPENE, SILACYCLOPROPANE, AND SILACYCLOPROPENE
复制标题
DOI：
10.1021/ja00545a002
复制
发表时间：
1980-01-01
影响因子：
15
通讯作者：
GORDON, MS
中科院分区：
文献类型：
--
作者：
GORDON, MS
利用适当的等键反应计算了四个三元环的应变能。用d函数和不用d函数对重原子的计算表明，虽然这些极化函数倾向于减小环应变，d轨道的加入对预测的趋势影响不大。虽然不饱和度的引入大大增加了碳体系(环丙烷-环丙烯)的应变，但对硅(硅环丙烷-硅环丙烯)却不是这样。因此，环丙烷和环丙烯分别被预测为应变最小和最大的环。环应变是一个经常被用来解释小环化合物的不稳定性和反应性的概念。最近，人们提出了一种新的环应变定量测量方法。1这种方法利用等键反应，其中每种类型的键的数目在从反应物到产物的过程中形式上是守恒的。由于关联误差的影响，等键反应的使用在量子化学中特别有用
The strain energy in four three-membered rings is calculated by using the appropriate isodesmic reactions. Calculations with and without d functions on the heavy atoms indicatethat while these polarization functions tendto reduce ring strain, the additionof d orbitals has little effect on the predicted trends. While introduciton of unsaturation drastically increases the strain in the carbon system (cyclopropane- cyclopropene), this is not the case for silicon (silacyclopropane-* silacyclopropene). As a result cyclopropane and cyclopropene are predicted to be the least and most strained rings, respectively.Ring strain is a concept which is frequently used to rationalize instability and reactivity of small cycliccompounds. Recently, a novel quantitative measure of ring strain has been proposed. 1 This method makes use of isodesmic reactions in which the number of bonds of each type is formally conserved on going from reactants to products. The use of isodesmic reactions is particularly useful in quantum chemistry since the effect of correlation error