The spectrum shows several interesting features and the proton assignment was complicated due to the complexity of the final product in the presence of impurities. First, there are doublets at 7.6 ppm, 7.8 ppm, and 8.07 ppm. These doublets may arise from structural cis-trans isomerism. The starting material diaminostilbene was only 85% pure and consequently the intermediate contains two isomers in 85:15 ratio(trans versus cis). More overlapping peaks from 7.2 to 7.3 ppm are assigned to the aromatic stilbene and aromatic ortho positions of tritylaniline. Six para protons of tritylaniline are located at 7.4 ppm. Two downfield peaks are present, one at 10.1 ppm and the other at 11.6 ppm. The peak at 11.6 ppm indicates that the nitrogen on the tritylaniline must be protonated. Protons on ammonium ions can occur as far downfield as 11.6 ppm [7]. The protonation of the nitrogen is due to the fact that when diaminostilbene is reacted with cyanuric chloride, HCl is formed as a side product and protonates the secondary nitrogen to form the HCl salt. The other downfield peak at 10.1 ppm is due to either nitrogen protonation of unreacted starting material or intermediate, or 3 SO groups on the aromatic rings becoming protonated at low pH. In addition to conventional characterization techniques such as 1HNMR, to determine purity, we also examined the products by diffusion ordered spectroscopy (DOSY) [8] as shown in Figure 7.