title: Speciation of Iron (III) Oxide Nanoparticles and Other Paramagnetic Intermediates during High-Temperature Oxidative Pyrolysis of 1-Methylnaphthalene.
abstract: Low Temperature Matrix Isolation - Electron Paramagnetic Resonance (LTMI-EPR) Spectroscopy was utilized to identify the species of iron oxide nanoparticles generated during the oxidative pyrolysis of 1-methylnaphthalene (1-MN). The otherwise gas-phase reactions of 1--MN were impacted by a polypropylenimine tetra-hexacontaamine dendrimer complexed with iron (III) nitrate nonahydrate diluted in air under atmospheric conditions. The EPR fine structure of Fe (III)2O3nanoparticles clusters, characterized by g-factors of 2.00, 2.28, 3.76 and 4.37 were detected on a cold finger maintained at 77 K after accumulation over a multitude of experiments. Additionally, a high valence Fe (IV) paramagnetic intermediate and superoxide anion-radicals, O2•-adsorbed on nanoparticle surfaces in the form of Fe (IV) --- O2•-were detected from the quenching area of Zone 1 in the gas-phase.
authors.affiliation: LSU, Department of Chemistry, Baton Rouge, LA, 70803 USA ( mherri7@lsu.edu ).
authors.forename: Michael P
authors.initials: MP
authors.lastname: Herring
authors.affiliation: LSU, Department of Chemistry, Baton Rouge, LA, 70803 USA (phone: 225 578 4417; lkhach1@lsu.edu ).
authors.forename: Lavrent
authors.initials: L
authors.lastname: Khachatryan
authors.affiliation: LSU, Department of Chemistry, Baton Rouge, LA, 70803 USA ( barryd@lsu.edu ).
authors.forename: Barry
authors.initials: B
authors.lastname: Dellinger
keywords: Cryogenic trapping; EPFRs; Fe2O3 doped silica; dendrimer; soot