Matrix isolation infrared and ab initio studies on conformers of 3-fluoropropene
| Autor: | Markku Räsänen, Janne Nieminen, Juhani Murto |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
010304 chemical physics
Infrared Chemistry Gaussian orbital General Engineering Matrix isolation Ab initio Infrared spectroscopy 010402 general chemistry 01 natural sciences Spectral line 0104 chemical sciences Computational chemistry Ab initio quantum chemistry methods 0103 physical sciences Physical chemistry Conformational isomerism |
| Zdroj: | Spectrochimica Acta Part A: Molecular Spectroscopy. 47:1495-1504 |
| ISSN: | 0584-8539 |
| DOI: | 10.1016/0584-8539(91)80243-c |
| Popis: | The infrared spectra of the cis and gauche conformers of 3-fluoropropene, CH 2 CHCH 2 F, were studied in Ne, Ar, Kr and Xe matrices. An infrared-induced cis to gauche rotamerization was found in Ar, Kr and Xe matrices. A thermal interconversion process was also found. Its direction was dependent upon the host, being the same as that of the IR process in Kr but reverse in Ar and Xe. In Ar and Xe matrices considerable site-splitting occurs in the IR spectra and a detailed analysis of the processes in different sites is given. An energy difference of 2.5±0.3 kJ mol −1 between the cis and gauche species was obtained on assuming that the gas phase equilibrium between the conformers is trapped upon deposition. A slow dark process from cis to gauche conformer was observed in Kr matrices at temperatures above 15 K, possibly due to tunnelling. Ab initio calculations were carried out on 3-fluoropropene. The torsional potential energy curve and spectra of the conformers were calculated at the MP2(full)16-31G** level and were compared with the experimental results. |
| Databáze: | OpenAIRE |
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