AlCl3 strongly promotes the Friedel-Crafts alkylations and almost leads to the entirely vanishing of the aromatic C-H vibrations (2980 cm -1 -3080 cm -1 ), the preservation of aromatic hydrogen moieties is observable for Fe-P-BP and SA-P-BP. The aromatic skeletal vibrations of Fe-P-BP and SA-P-BP reveal distinct peaks at 1607 cm -1 and 1487 cm -1 . For Al-P-BP, the first one possesses a more spread shape and the second one is absent, probably originating from more varying and more intensively substituted aromatic rings. Correspondingly, the patterns of the aliphatic C-H vibrations (2800 cm -1 -2980 cm -1 ) vary between Al-P-BP and the structurally close Fe-P-BP and SA-P-BP. In addition, the signal of the CH2 deformation vibrations (1376 cm -1 ) only emerges in Al-P-BP and can be attributed to a high density of alkylation bridges. In contrast to the AlCl3catalyzed polyphosphine, Fe-P-BP and SA-P-BP reveal more pronounced bands of C-O valence vibrations (1010 cm -1 -1190 cm -1 ) and a distinct C-Cl vibration (818 cm -1 ), suggesting the remaining of a higher amount of unreacted crosslinker functionalities. The thermal stability of the three polyphosphines was probed with thermogravimetric analysis (TGA) under nitrogen atmosphere (Fig. ). SA-P-BP does not show a mass loss up to 340 °C, after which a continuous mass loss occurs, followed by a sharp mass loss of 16 % at 490 °C. For Fe-P-BP and Al-P-BP, this two-step degradation process initiates already at 130 °C with a slow, continuous mass loss and is continued with a sharper slope at 340 °C. Overall, Al-P-BP exhibits 30 %, Fe-P-BP 21 % and SA-P-BP 23 % mass loss at 650 °C, indicating the differing structural properties, which relate to the choice of the Friedel-Crafts catalyst.