Mid-infrared laser magnetic resonance spectroscopy

Abstract

The development of laser magnetic resonance (l.m.r.) spectroscopy with CO (λ= 5–7 µm) and CO₂(λ= 9–11 µm) laser sources originally lagged behind the application of this technique in the farinfrared region. However, during the past five years, mid-infrared l.m.r. has been extensively used to study vibration–rotation and electronic spectra of a large number of atoms, diatomic molecules and triatomic molecules. It has allowed the study of many unstable free radicals that could not be detected by more conventional infrared techniques. This paper presents a brief review of these developments with an emphasis on recent work. Some new analyses of already published mid-infrared l.m.r. data are also presented. These are made possible by newly available measurements of isotopic CO₂ laser frequencies and improved ground vibrational state data, and they result in improved molecular parameters for the following molecules: HCO(ν₂), HO₂(ν₃), DO₂(ν₂), PH₂(ν₂) and ND₂(ν₂).