The infrared spectroscopy of a nitrogen matrix doped with mercury was revisited with an high resolution Fourier transform spectrometer. The detection of a new line and more accurate frequencies and intensities obliges us to revise the previous line attributions (Legay, F.; Legay-Sommaire, N.; Chandrasekharan, V. J. Phys. Chem. 1990, 94, 8548). The previous model is still valid on the condition that we modify the orientation of the twelve nearest neighbors around a mercury atom and introduce three different coupling constants. The vibrational emission lines of Nz in its ground electronic state have been measured from nu’ 5 to nu’ 16 and, in comparison with the gas phase data, show the variation of the matrix effect with the vibrational excitation. The presence of additional weak emission lines at low temperature suggests that small proportions of excited nitrogen molecules are in particular sites.