Moving to the calculations of the UV/vis spectra of the optimized structures, we also found that the catalyst/reactant complexes had intense absorption bands centered in the 425-450 nm range, which practically corresponded to the LED emission region. After optimizing the three-component geometry, we obtained a stable intermediate structure (where the CF3 carbon was on top of the para ring carbon at about 3.3 Å separation -Figure top configuration). Then, we calculated the UV-vis spectrum (Figure ), which revealed a dominant transition at about 434 nm (HOMO-3 LUMO) responsible for the formation of the F3C-C bond, as evidenced by the involved orbitals represented in Figure . Again, we optimized this intermediate complex, obtaining a bounded structure (movie in SI), and then predicted its UV absorption spectrum (Figure top left spectrum). This showed a dominant peak corresponding to a transition from the catalyst to the adsorbed complex (HOMO-16 to LUMO -Figure left orbitals). The excited state optimization produced the geometry corresponding to the transition state shown in Figure (structure in the middle), where the para-C-H was halfway from C to N. Then, the transfer to the closer nitrogen on the melamine unit was completed in the final optimized product (Figure bottom structure).