Berghof, V. and Martins, M. and Schmidt, B. and Schwentner, N. (2002) Vibrational Overtones and Rotational Structures of HCl in Rare Gas Matrices. J. Chem. Phys., 116 (21). pp. 93649373.

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Official URL: http://dx.doi.org/10.1063/1.1475752
Abstract
The rotational structure in the vibrational transitions from ν=0 to ν=1,2,3,4 of H35Cl and H37Cl is studied in Xe, Kr and Ar matrices with high spectral resolution. A consistent set of rotational constants Bv for the vibrational levels ν=0 to 4 is derived. B0 decreases with the tightness of the cage from 9.78 cm1 in Xe to 8.83 cm1 in Ar for H35Cl (gas phase 10.44 cm1). The values for B0 to B4 decrease linearly with v due to the vibrationrotationcoupling constant α which increases from 0.37 cm1 in Xe to 0.479 cm1 in Ar (gas 0.303) according to the cage tightness. The splitting of the R(1) transition which originates from the hindering of rotation is analyzed in Xe using the T2gT1u and T2gEg transition energies. A comparison with force field calculations yields a dominant contribution of the 6th spherical harmonic YA1g6 of the octahedral matrix potential. The modulation of the potential takes a value of K6/B=17 which corresponds to a barrier for the rotation of 160 cm1. The splitting increases with the vibrational level v which can be interpreted as a weak admixture of the YA1g4 spherical harmonic. A large isotope effect and a reduction of the T1uA1g transition energy (R(0)transition) beyond the crystal field value are attributed to an excentric rotation with a displacement of the center of mass of the order of 0.05 Å. The vibrational energies ωe show an opposite trend with matrix atom size and decrease with polarizability from 2970 cm1 in Ar to 2945.4 cm1 in Xe (gas 2989.9 cm1) while the anharmonicity ωeχe of the free molecule lies close to the Kr value and thus between that of Ar and Xe.
Item Type:  Article 

Subjects:  Mathematical and Computer Sciences > Mathematics 
Divisions:  Department of Mathematics and Computer Science > Institute of Mathematics Department of Mathematics and Computer Science > Institute of Mathematics > BioComputing Group 
ID Code:  78 
Deposited By:  Admin Administrator 
Deposited On:  03 Jan 2009 20:20 
Last Modified:  03 Mar 2017 14:39 
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