Electronic absorption spectroscopy of polycyclic aromatic hydrocarbons (PAHs) radical cations generated in oleum: a superacid medium.
Oleum (fuming sulphuric acid), a well known superacid, was used as medium for the generation of the radical cation of a series of selected PAHs. The resulting radical cation spectra were studied by electronic absorption spectroscopy. Not only common PAHs like naphthalene, anthracene, tetracene, pentacene, perylene, pyrene, benzo[a]pyrene, phenanthrene and picene were studied but also the less common and very large PAHs relevant also for the astrochemical research, like coronene, hexabenzocoronene, quaterrylene, dicoronylene and a coronene oligomer. A correlation between the first ionization potential (IP1) of the PAHs studied and the energy to the so-called A-type band of the radical cations observed in oleum has led to the equation IP1=1.30EA+4.39 (in eV) which permits to estimate the energy of the PAHs radical cation transition (EA) in the VIS-NIR knowing the relative ionization potential or vice versa.
Cataldo
Franco
F
Istituto Nazionale di Astrofisica-Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy. franco.cataldo@fastwebnet.it
Iglesias-Groth
Susana
S
Manchado
Arturo
A
D000042:Absorption; D000873:Anthracenes / Q000737:chemistry; D002412:Cations / Q000737:chemistry / Q000493:pharmacokinetics; D008954:Models, Biological; D009279:Naphthacenes / Q000737:chemistry; D009281:Naphthalenes / Q000737:chemistry; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000493:pharmacokinetics*; D013464:Sulfuric Acids / Q000737:chemistry* / Q000378:metabolism*
D000873:Anthracenes; D002412:Cations; D009279:Naphthacenes; D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D013464:Sulfuric Acids; C007229:decalin; C523499:pentacene; C034020:anthracene; C033158:sulfuric acid; C487736:naphthacene