Vibrational Spectra and Structure of Cyclopentane and its Isotopomers
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- 作者：Esther J. Ocola ; Leslie E. Bauman ; Jaan Laane
- 刊名：Journal of Physical Chemistry A
- 出版年：2011
- 出版时间：June 23, 2011
- 年：2011
- 卷：115
- 期：24
- 页码：6531-6542
- 全文大小：1234K
- 年卷期：v.115,no.24(June 23, 2011)
- ISSN：1520-5215
文摘
The infrared and Raman spectra of vapor, liquid, and solid state cyclopentane and its d1, 1,1-d2, 1,1,2,2,3,3-d6, and d10 isotopomers have been recorded and analyzed. The experimental work was complemented by ab initio and density functional theory (DFT) calculations. The computations confirm that the two conformational forms of cyclopentane are the twist (C2) and bent (Cs) structures and that they differ very little in energy, less than about 10 cm鈥? (0.1 kJ/mol). The bending angle for the Cs form is 41.5掳 and the dihedral angle of twisting is 43.2掳 for the C2 form. A reliable and complete vibrational assignment for each of the isotopomers has been achieved for the first time, and these agree very well with the DFT (B3LYP/cc-pVTZ) computations. The ab initio CCSD/cc-pVTZ calculations predict a barrier to planarity of 1887 cm鈥?, which is in excellent agreement with the experimental value of 1808 cm鈥?.