Experimental HR FTIR studies of the stability of the hydrogen chloride complexes with ethylene and acetylene

• Published in: Journal of molecular structure Vol. 563; pp. 215 - 220
• Main Authors: Mikulskiene, B, Gruodis, A, Sablinskas, V, Nelander, B
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 28-05-2001
• Subjects: Acetylene; Ethylene; Hydrogen chloride; Infrared spectroscopy; Van der Waals complexes; Infrared spectroscopy; Van der Waals complexes; Hydrogen chloride; Ethylene; Acetylene
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/S0022-2860(00)00878-4

A high resolution FTIR study of intermolecular interactions in van der Waals dimers, HCl–ethylene and HCl–acetylene, has been carried out. Partly resolved vibration–rotation spectral bands of the complexes are observed in the spectral region 2795–2820
cm
−1. Assignments of the vibrational spectral bands are made combining ab initio data with the experimental results. It is concluded that the very unsymmetrical shape of the P branches of A-type bands is due to an increase of the rotational constants
B and
C in the first vibrationally excited state of the HCl stretch of the complexed HCl. The ab initio calculations predict the existence of low wavenumber intermolecular fundamental vibrations whose first excited states have significant populations at the temperatures of the measurements. Hot bands due to these fundamentals have been observed in the spectra.