Reactions of laser-ablated Mo and W atoms with the N(2)O molecules in excess argon have been investigated using matrix-isolation infrared spectroscopy. In the reaction of the N(2)O molecule with the Mo atom, the absorptions at 1960.3 and 934.4 cm(-1) are assigned to the N-N and Mo-O stretching vibrations of the OMoNN complex, respectively. An analogous OWNN complex has also been observed in the W + N(2)O reaction. Infrared spectroscopy also provides evidence for the formation of the OW(NN)(2) complexes. Density functional theory calculations have been performed on the products. Overall agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts supports the identification of these species from the matrix infrared spectra. Furthermore, a plausible reaction mechanism for the formation of these products has been proposed.