High Resolution FTIR Spectroscopy of DCCCl: Anharmonic Resonances in the ν1 and ν2 Bands

Abstract

High-resolution infrared spectra of the ν1 and ν2 bands of DCCCl were observed using Bruker IFS 120HR Fourier transform spectrometers at resolutions of 0.0044 and 0.0035 cm−1, respectively. For the DCC35Cl isotopomer, the ν1 as well as the ν2 band was found to be heavily perturbed. Detailed analyses revealed that the ν1 state is in resonance with the l=0 substate of the ν3+4ν4 state and that the ν2 state is in resonance with the l=0 substate of the ν3+4ν5 state. The rotational constants played a key role in identifying the perturbing states. In contrast, for the DCC37Cl isotopomer, the rotational structures of the ν1 and ν2 states are almost regular but slightly perturbed by interactions with the ν3+4ν4 and ν3+4ν5 states, respectively. The constants of resonances as well as the molecular constants for the ν1, ν2, ν3+4ν4 and ν3+4ν5 states were determined.