G.A. Onopenko

High resolution vibration-rotation spectrum of the D2O molecule in the region near the 2ν1 + ν2 + ν3 absorption band

The high resolution Fourier transform spectrum of the D20 (ν = ν1 + ν2/2 + ν3 = 3.5) polyad was analysed within the framework of the Hamiltonian model taking into account resonance interactions between the seven states (310), (211), (112), (013), (230), (131) and (032). Transitions belonging to the 2ν1 + ν2 + ν3, 3ν1 +ν2 and 3ν2 + 2ν3 bands were assigned in the experimentally recorded spectrum. This provided the possibility of obtaining spectroscopic parameters of the ‘visible’ states (211), (310) and (032) and of estimating the band centres, and the rotational and resonance interaction parameters of the ‘dark’ states (112) and (131).

High resolution study of the ν5 + ν12 band of C2H4

The combination band ν5 + ν12 of ethylene, C2H4, has been recorded for the first time with a high resolution Fourier transform spectrometer Bruker IFS 125HR. Assignments of transitions and preliminary rotational analysis are made. Two models (Hamiltonian of the isolated vibrational state and Hamiltonian that takes into account resonance interactions) are used. Influence of the local resonance interactions on the parameters and reproduction power of the models is discussed.

HIGH RESOLUTION SPECTROSCOPIC STUDY OF H2SE (40+, 0) A1 AND (40-, 0) B2 STRETCHING STATES : NORMAL MODE AND LOCAL MODE ANALYSIS

High resolution spectra of the coupled and degenerate (40+, 0) A1 and (40-, 0) B2 (the local mode pair) states of H2Se are reported. The vibration–rotation transitions of H2 n Se (n = 80,78) were assigned by using the ground state combination differences and least-squares fits to yield the rotational and coupling constants for the two stretching states with degenerate band origins: υ0 (40+, 0) = 8894·504cm-1; υ0 (40-, 0) = 8894·504cm-1. Several striking local 0 0 mode limit effects and the formation of fourfold rovibrational energy clusters are observed and discussed.

Investigation of the Fine Rotational Structure of the Fourth (500; A1, E) Overtone of the AsH3 Molecule

The results of investigations into the high-resolution Fourier spectrum of the AsH3 molecule first registered in the range 9720–9900 cm–1 with a resolution of 0.015 cm–1 are given in the present paper. Lines of (500; A1) and (500; E) bands are interpreted by the method of combination differences. The spectroscopic constants of the examined arsine bands are determined by solving the inverse problem. They have allowed 98 rotational energy levels (with Jmax = 6) to be reproduced with errors close to the experimental ones.

Analysis of the Vibrational-Rotational Structure of 2ν1, ν1 + ν3, and 2ν3 Bands of the D2Se Molecule

The absorption spectrum of the D2Se molecule in the region of 2ν1, ν1 + ν3, and 2ν3 absorption bands is registered with a high-resolution Fourier spectrometer and is studied theoretically for a Hamiltonian model with allowance for resonant interactions among (200), (101), and (002) vibrational states.