The matrix infrared spectrum of PN and SiS

Gaseous PN and SiS have been prepared at high temperatures from P₃N₅ and from CS₂ + Si respectively, and the species have been trapped in krypton matrices at 10°K. Infrared studies using P¹⁴N and P¹⁵N showed matrix isolated PN monomer and its aggregation to P₃N₃, a molecule isostructural with Si₃O₃ with D_3h symmetry; P₂N₂ was not detected. Both SiS and Si₂S₂ were detected by i.r. in the SiS/Kr matrix but no higher polymers could be characterised. The molecular parameters of SiS and Si₂S₂ calculated from the infrared data are in line with those for other matrix isolated Group IV chalcogenides.