Study of vib-rotational spectra of van der Waals complexes containing SH4 and CH4

我们使用1998年在我们实验室建造的傅里叶变换微波（FTMW）机搜索了CD4- H20和GeH4- H20的旋转光谱。最近，我们成功地观察到了CD4- H20的旋转光谱，但是，我们无法检测到GeH4- H20的光谱，并且仍在寻找它。当搜索CH4—NO的旋转光谱时，观察到许多反式和顺式hono和N2O3的吸收谱线。接下来，我们考虑了如何解释已经使用FTMW光谱仪观察到的Ar—SiH4和Ar—SiD4光谱模式之间的差异。仅考虑一个科里奥利相互作用项（SiH4的内部旋转和配合物的端上端旋转耦合）很难解释观测到的光谱模式。然后，我们考虑了Ar—SiH4的范德华拉伸模式的各向异性势，并通过范德华键距离的幂级数展开了该势。为了拟合观测到的Ar- SiH4和Ar-的光谱模式。SiD4，选择的潜在订单分别为-15和-9。这些值对应于球形顶部分子的伦纳德-琼斯势的排斥力和引力。此外，我们试图通过考虑一般内旋海因顿量的对角化来解释观测到的SiH4—H20体系的旋转光谱。由于SiH4—H20具有较强的氢键作用，估计其势垒约为260 cm- 1。最后，通过分析LiBH4和NaBH4激发振动态的旋转谱，确定了它们的能量差和科里奥利相互作用常数。

We have searched for rotational spectra of CD4--H20 and GeH4--H20 using a Fourier transform microwave (FTMW) machine which was built in our lab in 1998. Very recently we succeeded in observing the rotational spectra of CD4--H20, However, we could not detect a spectrum of GeH4--H20 and are still searching it. When a rotational spectrum of CH4--NO was searched, many absorption lines of trans- and cis-HONO and N2O3 were observed. Next we considered how to explain the difference between the spectral patterns of Ar--SiH4 and Ar--SiD4 which had already been observed using a FTMW spectrometer. It was difficult to explain the observed spectral patterns considering only a Coriolis interaction term, which couples the internal rotation of SiH4 and the end-over-end rotation of the complex. Then we considered an anisotropic potential of a van der Waals stretching mode for Ar--SiH4 and expanded this potential by a power series of van der Waals bond distance. In order to fit the observed spectral patterns of Ar--SiH4 and Ar-. SiD4, the potential orders were chosen to be -15 and -9, respectively. These values were corresponded to the repulsive and attractive forces of the Lennard-Jones potential for a spherical top molecule. In the addition, we tried to explain the observed rotational spectra of SiH4--H20 system by taking account for a diagonalization of the general internal rotation Hainiltonian. The potential barrier of SiH4--H20 was estimated to be about 260 cm- 1 because of rather strong hydrogen bonding. Finally, analyzing the rotational spectra of the excited vibrational states for LiBH4 and NaBH4, the energy differences and the Coriolis interaction constants were determined.