Charge-transfer interaction of iodine with some polyamidoamines

The interaction of iodine as a σ-acceptor with two derivatives of polyamidoamine dendrimers (donor), 1,8-naphthalimide polyamidoamine (PAM1) and 4-piperidino-1,8-naphthalimide polyamidoamine (PAM2) have been investigated spectrophotometrically at room temperature in chloroform. The results indicate the formation of two CT-complexes [(PAM1)I]+I3− and [(PAM2)2I]+I3− with molar ratios of 1:2 and 1:1, respectively. The formation of these two complexes are in good agreement with their elemental analysis, infrared measurements and photometric titration plots based on the characteristic absorption bands of I3− ion around 280 and 360 nm. Moreover the formation of triiodide ion, I3−, in both of the two complexes was supported by measuring their spectra in the far-infrared region. Three characteristic bands are observed at 125, 110 and 75 cm−1 due to νas(I-I), νs(I-I) and δ(I3−), respectively, with C2v symmetry.