The molecular structure of pyrogenic organic matter (PyOM) is generally considered to exert a dominant control on PyOM-C mineralization, yet similar information is lacking for PyOM-N. In this study, we evaluated how the thermal conversion of organic matter (OM) into PyOM altered the N molecular structure and affected subsequent C and N mineralization. Nitrogen near edge X-ray absorption fine structure (NEXAFS) of uncharred OM, PyOM, PyOM toluene extract, and PyOM after toluene extraction were used to predict PyOM-C and –N mineralization potentials. PyOM was produced from three different feedstocks (e.g. Maize- Zea mays L.; Ryegrass- Lollium perenne L.; and Willow-Salix viminalix L.) each with varying initial N content at three pyrolysis temperatures (350, 500 and 700°C). Mineralization of C and N was measured from incubations of uncharred OM and PyOM in a sand matrix for 256 days at 30°C. This data set provides a library of nitrogen (1s) near-edge X-ray absorption fine structure (NEXAFS) spectra of organic N reference compounds and uncharred OM, PyOM, PyOM toluene extract, and PyOM after toluene extraction used in this study. The dataset also contains the C and N mineralization data used to correlated N molecular structure information to PyOM-C persistence in the environment. The datafiles include processed data and derived quantities.