Knowledge Bank

Electronic and vibrational (IR and Resonance Raman) spectra of the naphthalene cation and para-bromochlorobenzene cation in an Ar matrix (at 12K) have been recorded using a new experimental arrangement which allows the probing of the same sample matrix with three different spectroscopic probes along mutually perpendicular axes. They are visible/near IR along the x axis, IR along the y axis and Raman/resonance Raman along the z axis. This is advantageous from the point of view that usually only the electronic spectra are known for ionic species in matrices. Band intensity correlations (e.g., electronic vs IR or Raman) are very helpful for the assignment of newly observed IR or Raman bands for aromatic cations. The resonance Raman spectrum of naphthalene cation will be compared to the recently published ZEKE photoelectron spectrum of this $species1$.