摘要
用半经验量子化学方法ＡＭ１和ＰＭ３对竹红菌乙素及其溴代物进行了对比计算，考察了溴代作用对竹红菌乙素分子性质的影响。两种方法所得结果均表明，溴代作用使分子的生成热、前线轨道能级及偶极矩等参数都有所降低，溴代作用也影响了竹红菌乙素分子内氢键的性质，并能使其对光的吸收产生红移。
The semi-empirical quantum chemistry method AM1 and PM3 were used to calculate the molecules of hypocrellin B and its substitutes by bromine, the effect of bromation on the properties of hypocrellin B were also investigated. The results which obtained from AM1 and PM3 calculations showed that the heat of formation, HOMO or LUMO energy levels and dipole moment of all isomers of hypocrellin B are all lowed to a certain extent due to bromation. At the same time, the property of intramolecular hydrogen bond is changed and the wavelengths of light absorbed are increased for all substitutes of hypocrellin B by bromine according to AM1 and PM3 calculations.
