Charge-transfer interaction of iodine with some polyamidoamines

The interaction of iodine as a sigma-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]I-+(3)- and {[}(PAM2)(2)I](+)I-3(-) 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 I-3(-) ion around 280 and 360 nm. Moreover the formation of triiodide ion, I-3(-), 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 v(as)(I-I), v(s)(I-I) and delta(I-3(-)), respectively, with C-2v symmetry. (C) 2004 Elsevier B.V. All rights reserved.