Lifetime of 1Δ-oxygen molecules in rare gas matrices

Abstract The lifetime of electronically excited metastable 1 Δ-oxygen molecules being trapped as guests in rare gas matrices was measured. The decay was found to be strongly non-exponential with the momentary lifetime increasing from relatively short values immediately after the preparation of a matrix to a constant saturation value later on. This saturation lifetime is characteristic of the host material and ranges from 220 s in neon down to 48 s in xenon. The common relationship between lifetime and refractive index of the host matrix is qualitatively verified. Calculated (radiative) and measured (total) lifetimes differ by a nearly constant factor, which seems to be caused by additional non-radiative transitions in the matrix.