title: Structural and spectroscopic characterizations on the charge-transfer interactions of the second generation poly(propylene amine) dendrimers with iodine and picric acid acceptors.
abstract: 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 294 nm. Raman laser spectrum of the brown solid heptaiodide complex has two clearly vibration bands at 155 and 110 cm(-1) due to symmetric stretching νs(II) outer and inner bonds, respectively. The (1)H NMR spectra and differential scanning calorimetry (DSC) data of PPD2 charge-transfer complexes were discussed.
authors.affiliation: Department of Chemistry, Faculty of Science, Zagazig University, Egypt; Faculty of Applied Medical Science, Al Jouf University-Al Qurayate, Saudi Arabia.
authors.forename: Mohamed Y
authors.initials: MY
authors.lastname: El-Sayed
authors.affiliation: Chemistry Department, Faculty of Science, Taif University, P.O. Box 888, Al-Hawiah, Taif 21974, Saudi Arabia; Department of Chemistry, Faculty of Science, Port Said University, Port Said, Egypt. Electronic address: msrefat@yahoo.com.
authors.forename: Moamen S
authors.initials: MS
authors.lastname: Refat
mesh_terms: D000586:Amination; D050091:Dendrimers / Q000737:chemistry*; D004579:Electron Transport; D004583:Electrons; D007455:Iodine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010851:Picrates / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry*; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman
chemical_list: D050091:Dendrimers; D010851:Picrates; D011126:Polypropylenes; D007455:Iodine; C005858:picric acid
keywords: Dendrimer; Heptaiodide; Picric acid; Raman laser; Spectrophotometrically