The effect of heavy-atom solvents on the photooxidation of anthracene

Abstract

Photoirradiation of anthracene in benzene in the presence of oxygen gave predominantly a photodimer of anthracene, and very little oxidation product. Similar irradiation of anthracene in bromobenzene, however, produced 9,10-anthraquinone in high yield. The yield of anthraquinone increased in the presence of a heavy-atom solvent such as bromobenzene, p-dibromobenzene, 1,3,5-tribromobenzene, 1-bromopropane, and dibromomethane in proportion to the sum of squares of the spin–orbit coupling parameter ζ of the solvent molecule. This relationship indicates an external heavy-atom effect on the photooxidation of anthracene. The mechanistic investigations suggest the involvement of singlet oxygen, anthracene peroxide, and a radical intermediate in the formation of anthraquinone.

Efficient Synthesis of Anthraquinones from Diaryl Carboxylic Acids via Palladium(II)‐Catalyzed and Visible Light‐Mediated Transformations

“…To test the feasibility of this approach, we initially explored converting ethyl 2‐(anthracen‐9‐yl)acetate 2 a into anthraquinone 4 a with the visible light‐induced photooxidation process . The photooxidation mechanism of acenes was proposed to go through a photoinduced electron transfer redox process and radical coupling with superoxide –. An alternative reaction pathway involves formation of singlet oxygen ( 1 O 2 ) by the sensitizer, which reacts with acenes to afford endoperoxides.…”

Evaluation of the Use of Solar Irradiation for the Decontamination of Soils Containing Wood Treating Wastes

“…There are many possible mechanisms for the photodegradation of PAHs. Toshima et al 35 incorporated earlier work into a mechanistic study of anthracene which demonstrated the action of both free radical and singlet oxygen mechanisms in solution photooxidation reactions. Their results have been supported by others.…”

First Tribo‐Excited Chemical Reaction of a Stacked Lanthanide Coordination Polymer with an in Situ Reaction Monitor

“…The broad emission band with the characteristic vibrionic structure is assigned to the fluorescenceo f the dpa ligand in the Eu III coordination polymer.T his spectrum agrees with that of the bpa ligand ( Figure S4). The peaks in the narrowb ands are observed at 579, 594,6 13, 655, and 700 nm, which are assignedt ot he 5…”

“…The anthracene reacts with singlet oxygen ( 1 O 2 )g enerated by energy transfer from triplet anthracene ( 3 Ant) to triplet oxygen ( 3 O 2 ). [5] The stacked coordination polymer with hfaa nd aromatic bridged ligandsa lso induced CH-F interactions. The CH-F interactions promote the formation of tribo-excited states.…”