*3.4. NMR Characterization of Dendrimer ACR*

The chemical structure of the dendrimer ACR was confirmed by 1H and 13C NMR spectroscopy. The 1H NMR data show the evidence for the bonding of acridine fluorophore to the primary amino group from the dendrimer structure. From Scheme 1 it is clearly seen that the chemical structure of the polypropylene imine dendrimer is composed only of methylene groups (−CH2−) and their characteristic signals are in the spectral range δ = 1.22–3.60 ppm. These signals were observed at polypropylene imine dendrimers modified with 1,8-naphthalimide or benzanthrone fluorophores [32,33]. The aromatic proton (Ar−H) signals from the acridine structure are recorded in the δ = 7.03–7.89 ppm region as broad singlets. The carbon signals for acridine ring (Ar−C) are at δ = 115–152 ppm and that of the methylene groups −CH2− group of the poly(propylene imine) dendrimer framework are between δ = 23–55 ppm.
