Infrared identification of the Pt(N2) and Pt(N2)2 complexes in low temperature matrices

Several binary ${\mathrm{Pt–N}}_2$ complexes have been observed in rare‐gas matrices and in pure N₂ matrices at 14 °K. The $\mathrm{N–N}$ stretching mode in the region 2050–2360 cm⁻¹ has been measured as well as changes in the atomic Pt absorption spectrum. Variation of N₂ concentration in the rare gases, controlled annealing, and isotopic substitution have led to the assignment of the $\mathrm{N–N}$ stretching modes of Pt(N₂) and Pt(N₂)₂. Several other complexes Pt_x (N₂)_y where either x or y is 2 or more could not be uniquely identified. Evidence is presented which strongly indicates that Pt atoms diffuse in Ar matrices more readily than do N₂ molecules.