First high resolution ro-vibrational study of the (0200), (0101) and (0002) vibrational states of MGeH4 (M=76,74)

•High resolution analysis of the 2v2/v2+v4/2v4 bands of 74GeH4 and 76GeH4.•High resolution Dyad-Pentad bands of 74GeH4 and 76GeH4.•Resonance interactions in spherical top molecules.•Determination of spectroscopic parameters.

The infrared spectra of GeH4 (88.1% of 76GeH4, 11.5% of 74GeH4, and a minor amounts of three other stable isotopic species in the sample) were measured in the region of 1450-2000cm−1 with a Bruker IFS 125HR Fourier transform interferometer (Nizhny Novgorod, Russia) and analyzed. 2254 transitions with Jmax=19 were assigned for the first time to the bands 2ν4(F2), 2ν4(E), ν2+ν4(F2), ν2+ν4(F1), 2ν2(A1) and 2ν2(E) of the 76GeH4 isotopologue. Numerous “hot” Dyad-Pentad transitions also were recorded and assigned for the first time in the region of 700-1080cm−1 (in general, about 1000 transitions). Rotational, centrifugal distortion, tetrahedral splitting, and interaction parameters for the (0002,F2), (0002,E), (0002,A1), (0101,F2), (0101,F1), (0200,A1) and (0200,E) vibrational states were determined from the fit of experimental line positions. The obtained set of parameters reproduces the initial experimental data with accuracy close to experimental uncertainties. Results of the analogous analysis of the 74GeH4 isotopologue (the number of assigned transitions is 309 “cold” and 99 “hot” ones) are presented also. Obtained from the weighted fit set of spectroscopic parameters of the effective Hamiltonian reproduces the initial experimental data with the drms better than 3×10−4cm−1.