The experimental determination of the torsional barrier and shape for disilane.
The experimental determination of the torsional barrier and shape for disilane.
复制标题
乙硅烷扭转势垒和形状的实验测定。
DOI：
--
复制
发表时间：
2006
影响因子：
4.4
通讯作者：
V. Horneman
中科院分区：
文献类型：
--
作者：
N. Moazzen;V. Horneman
首次在高压光程条件下使用Bruker IFS-120 HR傅里叶变换光谱仪以0.007 cm（-1）的光谱分辨率记录了乙硅烷的扭转光谱。光谱显示出六个不同的Q分支。最突出的Q分支在130 cm（-1）附近，这是扭转基频的四个分量的混合。在其余5个中，4个分配给第一个扭转热带（v（4）=2<--1），1个分配给第二个扭转热带（v（4）=3<--2）。确定了350多个过渡。从振动带nu（9）和nu（9）+nu（4）-nu（4）的频率出发，分析了扭振基频、第一扭振热带和低态组合差，从而刻画了基态扭振哈密顿量.势垒高度、势垒形状和关于Si-Si键的转动常数分别被确定为404.344（83）cm（-1）、2.255（65）cm（-1）和43208（28）MHz。模拟光谱与实验光谱的比较（μ||-mu（垂直））/mu（垂直）= -4（1）（对于扭转偶极矩）。该比率与乙烷的-3.39（6）相比很好。并与甲基硅烷和乙烷的分子参数进行了比较。
The torsional spectrum of disilane was recorded for the first time under high-pressure-pathlength conditions and at a spectral resolution of 0.007 cm(-1) using a Bruker IFS-120 HR Fourier transform spectrometer. The spectrum shows six distinct Q branches. The most prominent Q branch is near 130 cm(-1) which is a blend of four components of the torsional fundamental. Of the remaining five, four were assigned to the first torsional hot band (v(4)=2<--1) and one to the second torsional hot band (v(4)=3<--2). Over 350 transitions were identified. An analysis of the torsional fundamental, the first torsional hot band, and the lower state combination differences from frequencies of the vibrational bands nu(9) and nu(9)+nu(4)-nu(4) was made to characterize the torsion-rotation Hamiltonian in the ground vibrational state. The barrier height, barrier shape, and the rotational constant about the Si-Si bond were determined to be 404.344(83) cm(-1), 2.255(65) cm(-1), and 43208(28) MHz, respectively. Comparison of simulated and the experimental spectra yielded (mu||-mu(perpendicular))/mu(perpendicular)= -4(1) for the torsional dipole moments. This ratio compares well with -3.39(6) for ethane. A comparison of molecular parameters obtained here is made with those for methyl silane and ethane.