Knowledge Bank

High resolution spectrum of $CHD3$ (instrumental resolution $0.0035cm-1$) was recorded on the Bruker IFS 120HR Fourier transform spectrometer (Oulu) and analyzed in the region of $1900-2800cm-1$. Spectrum in this region contains two strong fundamental bands $\nu 2(A1)$ and $\nu 4(E)1$ and some weak combination and overtone bands $2\nu 3(A1),\nu 3+\nu 6(E),2\nu 6(A1),2\nu 6(E),\nu 3+\nu 5(E),\nu 5+\nu 6(A1),\nu 5+\nu 6(E),2\nu 3(A1)$, and $2\nu 5(E)$. There are only few detailed studies of spectrum in this region . However, even at the recent paper (d) parameters were not determined which would reproduce initital experimental data with satisfactory accuracies. We used for analisys specially derived model of Hamiltonian which based on the irreducible tensorial sets theory. Taking into account a).higher-order resonance interactions between above mentioned vibration-rotation bands and b).higher-order splitting parameters we obtained set of spectroscopic constants which reproduce initial experimental data with the accuracies near to experimental uncertainties. Anomalous behaviour of $A1-A2$ splittings in $E$-type vibrational states and anomalous shifts of energy levels in $A1$-type vibrational states are discussed. Part of this work was supported by Russian Foundation on Fundamental Researches (Pr.N95-03-08081a).