Rotational spectra of four of the five conformers of 1-pentene
Rotational spectra of four of the five conformers of 1-pentene
复制标题
1-戊烯五种构象异构体中四种的旋转光谱
DOI：
10.1063/1.481220
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
C. Lugez
中科院分区：
文献类型：
--
作者：
G. T. Fraser;Li;R. Suenram;C. Lugez
The rotational spectra of four of the five expected conformers of 1-pentene, together with their monosubstituted 13C isotopic forms, have been measured in a molecular beam using a pulsed-nozzle Fourier-transform microwave spectrometer. One of the conformers has Cs point-group symmetry while the other three conformers have C1 point-group symmetry. The measurements are compared to results from molecular modeling calculations using the MM3 molecular-mechanics force field of Allinger et al. and to ab initio electronic structure calculations (MP2/6-31G*, MP2/6-311G*, MP4/6-31G*, MP4/6-311G*). Both types of calculations suggest the existence of five distinct conformers of 1-pentene, four of C1 symmetry and one of Cs symmetry. Both the MM3 and ab initio rotational constants deviate from the measured values by ⩽5%. The relatively high barriers between the four conformers limit the conformational cooling in the expansion, allowing all four conformers to be observed at the <2 K rotational temperature of the molecul...
