fulltext.study @t Gmail

A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione

Paper ID Volume ID Publish Year Pages File Format Full-Text
28376 44072 2009 7 PDF Available
Title
A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione
Abstract

The photochemical hydrogen abstraction reaction of pyrene-4,5-dione (3) has been investigated by laser flash photolysis. Excitation (λ = 355 nm) of a degassed solution of 3 in acetonitrile resulted in the formation of a detectable transient with absorption maxima at 380 and 470 nm. This transient decays with a lifetime of around 4.8 μs and is quenched by oxygen. This transient is most probably a triplet state of 3. Addition of hydrogen donors, such as 2-propanol; 1,4-cyclohexadiene or 4-methoxyphenol led to the formation of a new transient with λmax at 380, 500 nm and a broad absorption at 640 nm. This new transient slowly decays with second order kinetics and was assigned to the semiquinone radical obtained from the hydrogen abstraction reaction. Using DFT and AIM calculations the reactivity of 3 and 9,10-phenanthrenequinone (1) is best interpreted as a proton coupled electron transfer like mechanism for the hydrogen abstraction from 2-propanol.

Keywords
Laser flash photolysis; Ortho-quinone; Triplet excited state; DFT; Hydrogen atom transfer
First Page Preview
A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 201, Issue 1, 1 January 2009, Pages 1–7
Authors
, , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us