Calculation of Energy Levels for Internal Torsion and Over‐All Rotation. II. CH3CHO Type Molecules; Acetaldehyde Spectra
Calculation of Energy Levels for Internal Torsion and Over‐All Rotation. II. CH3CHO Type Molecules; Acetaldehyde Spectra
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CH3CHO 型分子的能级计算；
DOI：
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发表时间：
1957
期刊：
影响因子：
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通讯作者：
E. Wilson
中科院分区：
文献类型：
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作者：
R. W. Kilb;C. Lin;E. Wilson
描述了具有一个对称平面和一个对称内部转子的分子的全面旋转和内部扭转能级的计算方法。典型的有CH3CHO、CH3SiH2D和CH3OH。对CH3CHO、CD3CDO、CD3CHO、CH2DCHO、CHD2CHO、C13H3CHO、CH3C13HO、C13H3C13HO和CH3CHO18的微波光谱分析，前3种同位素的内旋势垒为V= v3 (1-cos3α)/2+ v6 (1-cos6α)/2，分别得到v3 =1162、1151、1143±30 cal和v6 <100 cal。在甲基的平衡取向中，醛氧位于其中一个甲基氢的对面。测定的9种同位素的转动惯量得到的结构参数为：甲基：C - h =1.086 a C - d =1.088 H-C-H =108°16 ' D-C-D =108°32 ' C - C=1.501醛：C - h =1.114 C=0=1.216 C - C - h =117°29 ' C - C - o =123°55 ' Stark效应得到的偶极矩为2.69 debyes。
Methods are described for the calculation of energy levels for the over‐all rotation and internal torsion of molecules with a plane of symmetry and one symmetric internal rotor. Typical examples are CH3CHO, CH3SiH2D, and CH3OH. Analysis of the microwave spectra of CH3CHO, CD3CDO, CD3CHO, CH2DCHO, CHD2CHO, C13H3CHO, CH3C13HO, C13H3C13HO, and CH3CHO18 yields V 3=1162, 1151, 1143±30 cal, and V 6<100 cal, respectively, for the first three isotopic species, where the barrier to internal rotation is V=V 3(1—cos3α)/2+V 6(1—cos6α)/2. The aldehyde oxygen was found to be opposite one of the methyl hydrogens in the equilibrium orientation of the methyl group. The measured moments of inertia of the nine isotopic species lead to a structure with the parameters Methyl group: C–H=1.086 A C–D=1.088 H–C–H=108°16′ D–C–D=108°32′ C–C=1.501 Aldehyde: C–H=1.114 C=0=1.216 C–C–H=117°29′ C–C–O=123°55′ The Stark effect gave a dipole moment of 2.69 debyes.