Vacuum Ultraviolet Spectrum of SiO in an Argon Matrix

The absorption spectrum of SiO isolated in an argon matrix has been investigated in the region 1200-2500 A using synchrotron radiation for the background continuum. Three vibrational progressions were observed in the matrix spectrum. They have been identified with the corresponding gas phase systems, the A1 Π-X1 Σ+, E1 Σ+-X1 Σ+ and G1 Π-X1 Σ+ systems.