Ring-puckering motion in cyclopentene studied by time-resolved rotational coherence spectroscopy and ab initio calculations.
Phys Chem Chem Phys
; 12(29): 8190-200, 2010 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-20390150
ABSTRACT
The ring-puckering vibration in cyclopentene was studied by rotational time-resolved femtosecond degenerate four-wave mixing (fs DFWM) spectroscopy. The fs DFWM spectra of cyclopentene were measured both in a supersonic expansion and in a gas cell at room temperature. The room temperature fs DFWM spectrum has been satisfactorily reproduced by a fitted simulation based on a one-dimensional model for the ring-puckering vibration. This has allowed for the determination of energetic parameters of the ring-puckering motion such as the energy barrier to ring inversion of 274(+12/-20) cm(-1) and the equilibrium ring-puckering angle of 24.3 degrees . The derived dependences of the rotational constants A and B on the puckering angle resemble very closely those obtained by microwave spectroscopy. In addition, previous theoretical estimates of the ring inversion barrier of cyclopentene were improved by performing high level ab initio calculations. Zero-point vibrational energy correction was found to be essential for an accurate evaluation of the puckering potential. Altogether, this study provides a proof-of-principle of the applicability of the fs DFWM technique for investigating large amplitude intramolecular motions.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Alemania