Abstract
Speculated structure of [(PPD2)(PA)4] charge-transfer complex. [Display omitted]
•Charge transfer complexes of poly(propylene amine) dendrimer were discussed.•The resulted data refereed to the formation of [(PPD2)(PA)4] and [(PPD2)]+I7− complexes.•Raman laser spectrum has studied the heptaiodide complex.•1H NMR spectra and differential scanning calorimetry (DSC) were performed.
Herein, this study was focused to get a knowledge about the intermolecular charge transfer complexes between the second generation of poly(propylene amine) dendrimer (PPD2) with picric acid (PA) and iodine (I2) as π and σ-acceptors. The charge-transfer interaction of the PPD2 electron donor and the PA acceptor has been studied in CHCl3. The resulted data refereed to the formation of the new CT-complex with the general formula [(PPD2)(PA)4]. The 1:4 stoichiometry of the reaction was discussed upon the on elemental analysis and photometric titration. On the other hand, the 1:3½ iodine-PPD2 heptaiodide (I7−) charge-transfer complex has been studied spectrophotometrically in chloroform at room temperature with general formula [(PPD2)]+I7−. The electronic absorption bands of 2I2·I3− (I7−) are observed at 358 and 294nm. Raman laser spectrum of the brown solid heptaiodide complex has two clearly vibration bands at 155 and 110cm−1 due to symmetric stretching νs(II) outer and inner bonds, respectively. The 1H NMR spectra and differential scanning calorimetry (DSC) data of PPD2 charge-transfer complexes were discussed.