Several new platinum nitride species are produced by the reaction of laser-ablated platinum with pure nitrogen, and their frequencies calculated by density functional theory in addition to the complexes observed in earlier thermal atom studies. Platinum forms PtN and a number of molecules derived from PtN including NNPtN, PtPtN, Pt2N, and PtNNPt, and PtNNN from reaction with N-3 radical in pure nitrogen. The PtNN complex is characterized by the Pt-N stretching mode at 499.6 cm(-1) and its combination band at 2669.6 cm(-1) with the strong N-N fundamental at 2168.5 cm(-1) in solid argon. Absorptions are observed for PtxNN, PtNN-, Pt(NN)(2)(-), and Pt(NN)(2) in solid argon and neon.