High-Resolution Infrared Synchrotron Investigation of (HCN)2 and a Semi-Experimental Determination of the Dissociation Energy D0.
Chemphyschem
; 20(23): 3238-3244, 2019 12 03.
Article
en En
| MEDLINE
| ID: mdl-31702872
ABSTRACT
The high-resolution infrared absorption spectrum of the donor bending fundamental band ν 61 of the homodimer (HCN)2 has been collected by long-path static gas-phase Fourier transform spectroscopy at 207â
K employing the highly brilliant 2.75â
GeV electron storage ring source at Synchrotron SOLEIL. The rovibrational structure of the ν 61 transition has the typical appearance of a perpendicular type band associated with a Σ-Π transition for a linear polyatomic molecule. The total number of 100 assigned transitions are fitted employing a standard semi-rigid linear molecule Hamiltonian, providing the band origin ν0 of 779.05182(50)â
cm-1 together with spectroscopic parameters for the degenerate excited state. This band origin, blue-shifted by 67.15â
cm-1 relative to the HCN monomer, provides the final significant contribution to the change of intra-molecular vibrational zero-point energy upon HCN dimerization. The combination with the vibrational zero-point energy contribution determined recently for the class of large-amplitude inter-molecular fundamental transitions then enables a complete determination of the total change of vibrational zero-point energy of 3.35±0.30â
kJ mol-1 . The new spectroscopic findings together with previously reported benchmark CCSDT(Q)/CBS electronic energies [Hoobler etâ
al. ChemPhysChem. 19, 3257-3265 (2018)] provide the best semi-experimental estimate of 16.48±0.30â
kJ mol-1 for the dissociation energy D0 of this prototypical homodimer.
Texto completo:
1
Banco de datos:
MEDLINE
Idioma:
En
Año:
2019
Tipo del documento:
Article