The starting point for this work is the ionothermal synthetic protocol for PTI that has not been altered since its first reports. The significant parameters for polycondensation reactions are the reaction temperature (600 °C) and the reaction time (12 h). The product is characterized as a dark brown powder (Figure , center). The material shows no visible photoluminescence under 375 nm UV-light (Figure ). Higher luminescence can typically be accessed only by dispersing the material in water/methanol/DMSO. Hence, it is often argued that the emission of the material in its initial graphitic state is quenched by π-π stacking. Instead of excitation and radiative emission, π-π quenching leads to photo induced electron transfer to a neighboring π-system. This inhibits effective recombination of the electron hole pair in a radiative process. We report that synthesis at a temperature of 550 °C and extended reaction times of 48 h yields an almost colorless product (Figure , left) with visible photoluminescence when irradiated with UV-light. The hitherto employed harsh reaction conditions (600 °C, 12 h) are at the onset of carbonisation of the material and introduce carbonaceous contaminants that darken the color of PTI. Qualitative and quantitative XPS analysis of the C1s core region shows an intense peak at 285 eV and confirms the presence of C-C environments (adventitious C1s, C-C peak at 284.8 eV) (Figure ). This contribution is often assigned to adventitious carbon. However, at 550 °C the contribution at 285 eV in the C1s spectrum of PTI-LiBr is greatly reduced. Since the contribution of adventitious carbon should be similar for all samples, we deduce that part of this contribution comes from a carbon rich phase that coevolved during the synthesis at 600 °C. Looking at the N1s region, we observe nitrogen signals from triazine moieties at 398.5 eV and a contribution from the imide-NH bridges between the triazine units at 400 eV with relative intensities of (3:1) for the product from 550 °C (Figure , right). The product obtained at 550 °C, 48 h approaches the theoretical elemental composition of poly(triazine imide) (C6N9H3) of 40:60 C:N most closely (Table ). Other groups have not reported the presence of this carbon-rich phase at these conditions. Hence it is likely that it was either overlooked or mistaken for a contribution solely from carbon tape used as substrate or adventitious carbon in XPS experiments. An attempt to study the structure of the phase obtained from 600 °C for 72 h was conducted by Suter et al. Table . X-ray photoelectron spectroscopy (XPS) analysis of atomic percentage of carbon and nitrogen observed in CN films prepared from different synthetic conditions. The integration of the carbon signal was conducted over all carbon species and not corrected for adventitious carbon.