(650 cm -1 -760 cm -1 ) coincide with the spectrum of the monomeric PPh3 and are complemented by respective substitution patterns. P-DCE and P-FDA show similar vibrations of the aromatic ring skeleton (1500 cm -1 -1760 cm -1 ) and deformation vibrations of CH2 groups (1373 cm -1 ), which are absent for P-DCM. Additionally, they exhibit corresponding vibrations of the aliphatic C-H bonds (2800 cm -1 -2980 cm -1 ), which are less pronounced for P-DCM. This distinction is reinforced by the preservation of the aromatic C-H vibrations (2980 cm -1 -3080 cm -1 ) of PPh3 in P-DCM, which are scarcely observable for P-DCE and P-FDA. the aromatic region of spectra of P-FDA (δ = 131.9 ppm) and P-DCE (δ = 131.5 ppm) are slightly shifted downfield, resulting in a left-sided shoulder. Such shift and the presence of the shoulder signal is most probably caused by the higher degree of aromatic substitutions in the Friedel-Craft alkylations with FDA and DCE compared to DCM. This hypothesis is underlined by the strong overlapping signals in the aliphatic region of the spectra of P-FDA and P-DCE, which are not present in the spectrum of P-DCM. The spectrum of P-DCE shows a peak at δ = 37.9 ppm, related to ethylene bridges and a peak at δ = 14.8 ppm, which is attributed to terminal alkyl substituents and whose occurrence was already reported in the AlCl3-catalyzed HCP synthesis. The aliphatic nuclei account for 29 % of the carbon atoms, meaning that 7. Finally, the spectra of P-FDA and P-DCE exhibit broad signals at about 200 ppm, which may result from carbonyl species formed by oxidation of terminal substituents.