Knowledge Bank

The infrared spectra of ClCN and BrCN in argon and krypton matrices at $20\circ K$ have been investigated. There is good evidence that for the monomeric species in the matrices, the bending mode is split by the matrix environment and that the first overtones of these two bending components form a Fermi resonant triad with the $v1$ fundamental. The frequencies and relative intensities of the three bands have been used to calculate unperturbed frequencies and Fermi coupling constants. The absorption bands due to dimeric species are consistent with a linear configuration for the dimer.