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借助MNDO、AM 1、HF/ 3 2 1G、HF/ 6 31G 量子化学理论计算方法 ,对 9 羟基苯并萘酮 (9 HPO)的分子内氢传递过程进行了理论探讨 ,并与X射线衍射的结构数据作了比较。发现 :1 .A构型的 9 HPO比B构型的更稳定 ,两个等同的A可以通过分子内氢传递相互转化 ,反应的过渡态就是B .2 .B是一种严格对称的平面构型 ,它的H电荷和偶极矩都较A增大 ,所以分子内氢传递速率在极性溶剂中将加快。3.共轭在 9 HPO分子内氢传递反应中起了重要的作用。 4.对于类似分子IHT的计算 ,先用半经验方法或小基组的从头计算方法优化结构 ,再用大基组的从头计算方法计算单点能可以得到较好的结果。
With the aid of MNDO, AM 1, HF / 3 2 1G and HF / 6 31G quantum chemistry theory, the intramolecular hydrogen transfer of 9-hydroxybenzo-pentanone (9 HPO) has been theoretically investigated and compared with the X-ray diffraction Structure data are compared. It is found that the 9 HPO of A.A configuration is more stable than the B configuration and the two equivalent A can be transformed into each other by intramolecular hydrogen transfer. The transition state of the reaction is B.2.B is a strictly symmetrical planar structure Type, its H charge and dipole moment are larger than A, so the rate of intramolecular hydrogen transfer in polar solvents will speed up. Conjugation plays an important role in the hydrogen transfer reaction of 9 HPO molecules. 4. For the calculation of IHT of similar molecules, we can optimize the structure by using the semi-empirical method or the ab initio calculation method of the small group, and then calculate the single-point energy by the ab initio calculation method of the large group.