THF/H~2O二元团簇中“幻数”现象研究

利用分子束、同步辐射光源和飞行时间质谱研究了HF/H~2O二元团簇体系，观察到了一系列组成为(THF)~n·(H~2O)~mH^+(n=2～5,m=0～n-1)离子峰，其中(THF)~n(H~2O)~n~-~2H^+(n=2～5)离子峰强为“幻数”峰。运用从头算(abinitio)分子轨道法，在HF/3-21G基组水平上对(THF)~n(H~2O)~n~-~2H^+(n=2～4)团簇几何构型进行了优化，计算结果表明团簇离子(THF)~n(H~2O)~n~-~2H^+具有较大的稳定性，解释了实验中观察到的“幻数”现象。

Study of the magic numbers for THF/H~2O binary clusters

The THF/H2O binary clusters have been studied by the molecular beam, the VUV from synchrotron radiation and the TOF mass spectrometry technique. The (THF)n (H2O)mH (n=2-5,m=0-n- 1) cluster ions were observed in the mass spectroscopy. It was noticed that the (THF)n (H2O)n-2H (n = 2-5) cluster ions had larger intensity than the others and were regarded as "magic number" ions. By using ab initio MO method at HF/3 - 21G basis set level, the structures of (THF)n (H2O)n-2H (n=2-4) cluster ions have been optimized. The theoretical calculations help to explain the "magic number" appearance in the experiment and are in agreement with the experimental results.