Abstract
The ultrafast photofragmentation of acetyl-benzoyl peroxide (ABPO) and 2-naphthoyl-benzoyl peroxide (NBPO) after UV excitation at 266 nm is studied by mid-infrared transient absorption spectroscopy. 13C-isotopic labelling is employed to unravel the primary fragmentation paths. For NBPO it appears that excitation of the benzoyloxy part causes decarboxylation exclusively at that site. In ABPO the acetyloxy part completely decarboxylates upon 266 nm excitation while only 80% – 85% of the benzoyloxyl radicals formed decarboxylate. The remaining radicals either combine with methyl radicals to methylbenzoate within about 30 ps or survive on the time scale of the experiment (1.5 ns). Photofragmentation of ABPO occurs from the S1-state whose lifetime is about 200 fs. All fragmentation products including CO2 also appear on this time scale.
Acknowledgement
We would like to thank Jens Schimpfhauser and Jürgen Bienert who synthesized the compounds needed for this study, and the Deutsche Forschungsgemeinschaft for financial support (SCHR 303/3-1; SCHW 661/3-1).
©2015 Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Frontmatter
- Preface
- Congratulations to Jürgen Troe
- The Kinetics of the Reaction C2H5• + HI → C2H6 + I• over an Extended Temperature Range (213–623 K): Experiment and Modeling
- Collisional Relaxation of NCN: An Experimental Study with Laser-Induced Fluorescence
- Reaction of Chlorine Molecules with Unsaturated Submicron Organic Particles
- Theoretical Kinetics Study of the Reactions Forming the ClCO Radical Cycle in the Middle Atmosphere of Venus
- On the Relation between Population Kinetics and State-to-State Rate Coefficients for Vibrational Energy Transfer
- Investigation of the ν2 + 2ν3 Subband in the Overtone Icosad of 13CH4 by Pulsed Supersonic Jet and Diode Laser Cavity Ring-Down Spectroscopy: Partial Rovibrational Analysis and Nuclear Spin Symmetry Conservation
- The Rotationally-Resolved Absorption Spectrum of Formaldehyde from 6547 to 7051 cm−1
- Constraining the Conformational Landscape of a Polyether Building Block by Raman Jet Spectroscopy
- The Reaction Kinetics of Amino Radicals with Sulfur Dioxide
- Challenging High-Level ab initio Rovibrational Spectroscopy: The Nitrous Oxide Molecule
- Reaction of the CF3 Radical with Various Cations (Ar+, Xe+, O2+, NO+, CO2+, C2F5+)
- Electronic Spectra of Corannulenic Cations and Neutrals in Neon Matrices and Protonated Corannulene in the Gas Phase at 15 K
- Photoionization Yields in Intense fs-Laser Fields – A Systematic Investigation of Chirp Effects
- Determination of the Temperature-Dependent OH− (H2O) + CH3I Rate Constant by Experiment and Simulation
- Can we Observe Gas Phase Nucleation at the Molecular Level?
- Multiphoton Ionization of Liquid-to-Supercritical Methanol. Ultrafast Dynamics of Electron Localization and Geminate Recombination
- Femtosecond Infrared Spectroscopy of Aroylperoxide Photofragmentation – Site Selective Decarboxylation
- Excited State Dynamics of Selected All-trans C40 Xanthophyll Carotenoids
- Complexation and Chiral Recognition of Chiral Binaphthyl Derivatives and β-Cyclodextrins in Solution Probed by Triplet Excited State Relaxation
- Ionic Solutions Probed by Resonant Inelastic X-ray Scattering
- Ordering Phenomena in Surfactant Systems: From Micellar Solutions to Gel and Crystalline Phases
- Investigation of the Growth Behaviour of Cobalt Thin Films from Chemical Vapour Deposition, Using Directly Coupled X-ray Photoelectron Spectroscopy
- Ultrafast Dynamics of the Indoline Dye D149 on Mesoporous ZnO and Al2O3 Thin Films
- Observation of Translation-to-Vibration Excitation in Acetylene Scattering from Au(111): A REMPI Based Approach
Articles in the same Issue
- Frontmatter
- Preface
- Congratulations to Jürgen Troe
- The Kinetics of the Reaction C2H5• + HI → C2H6 + I• over an Extended Temperature Range (213–623 K): Experiment and Modeling
- Collisional Relaxation of NCN: An Experimental Study with Laser-Induced Fluorescence
- Reaction of Chlorine Molecules with Unsaturated Submicron Organic Particles
- Theoretical Kinetics Study of the Reactions Forming the ClCO Radical Cycle in the Middle Atmosphere of Venus
- On the Relation between Population Kinetics and State-to-State Rate Coefficients for Vibrational Energy Transfer
- Investigation of the ν2 + 2ν3 Subband in the Overtone Icosad of 13CH4 by Pulsed Supersonic Jet and Diode Laser Cavity Ring-Down Spectroscopy: Partial Rovibrational Analysis and Nuclear Spin Symmetry Conservation
- The Rotationally-Resolved Absorption Spectrum of Formaldehyde from 6547 to 7051 cm−1
- Constraining the Conformational Landscape of a Polyether Building Block by Raman Jet Spectroscopy
- The Reaction Kinetics of Amino Radicals with Sulfur Dioxide
- Challenging High-Level ab initio Rovibrational Spectroscopy: The Nitrous Oxide Molecule
- Reaction of the CF3 Radical with Various Cations (Ar+, Xe+, O2+, NO+, CO2+, C2F5+)
- Electronic Spectra of Corannulenic Cations and Neutrals in Neon Matrices and Protonated Corannulene in the Gas Phase at 15 K
- Photoionization Yields in Intense fs-Laser Fields – A Systematic Investigation of Chirp Effects
- Determination of the Temperature-Dependent OH− (H2O) + CH3I Rate Constant by Experiment and Simulation
- Can we Observe Gas Phase Nucleation at the Molecular Level?
- Multiphoton Ionization of Liquid-to-Supercritical Methanol. Ultrafast Dynamics of Electron Localization and Geminate Recombination
- Femtosecond Infrared Spectroscopy of Aroylperoxide Photofragmentation – Site Selective Decarboxylation
- Excited State Dynamics of Selected All-trans C40 Xanthophyll Carotenoids
- Complexation and Chiral Recognition of Chiral Binaphthyl Derivatives and β-Cyclodextrins in Solution Probed by Triplet Excited State Relaxation
- Ionic Solutions Probed by Resonant Inelastic X-ray Scattering
- Ordering Phenomena in Surfactant Systems: From Micellar Solutions to Gel and Crystalline Phases
- Investigation of the Growth Behaviour of Cobalt Thin Films from Chemical Vapour Deposition, Using Directly Coupled X-ray Photoelectron Spectroscopy
- Ultrafast Dynamics of the Indoline Dye D149 on Mesoporous ZnO and Al2O3 Thin Films
- Observation of Translation-to-Vibration Excitation in Acetylene Scattering from Au(111): A REMPI Based Approach