Accuracy of Calculations of Heats of Reduction/Hydrogenation: Application to Some Small Ring Systems
作者:Kenneth B. Wiberg
DOI:10.1021/jo302118b
日期:2012.11.16
satisfactory than the others. Large basis sets are usually needed in order to reproduce experiments. Some C–C bond hydrogenolysis reactions also have been examined including those of bicycloalkanes and propellanes. In addition, the dimerization of the remarkably strained bicyclo[2.2.0]hex(1,4)ene was studied. The reaction forming a pentacyclic propellane was calculated to have ΔH = −57 kcal/mol, and the cleavage
在HF,B3LYP,M06,MP2,G3,G4,CBS-QB3,CBS-APNO和W1BD浓度下,已计算出羰基化合物还原和烯烃氢化的焓,在前四种方法中,使用各种基础设置,直到aug-cc-pVTZ。将结果与可用的实验数据进行比较,发现复合方法通常比其他方法更令人满意。通常需要大的基础集才能重现实验。还研究了某些C–C键氢解反应,包括双环烷烃和螺旋桨的氢解反应。另外,研究了显着应变的双环[2.2.0] hex(1,4)烯的二聚作用。计算形成五环丙烷的反应具有ΔH= -57kcal / mol,并且丙炔的裂解得到二烯的ΔH= -71kcal / mol。估计了这些化合物的应变能。