Carbon‐Centered Free Radicals and Radical Cations

Abstract

About the Volume Editor. Preface to Series. Introduction. Contributors. 1. A Brief History of Carbon Radicals (Malcolm D. E.Forbes). 2. Intermolecular Radical Additions to Alkynes: Cascade-TypeRadical Cyclizations (Uta Wille). 2.1 Introduction. 2.2 Cascade Reactions Involving Radicals of Second RowElements. 2.3 Cascade Reactions Initiated by Addition of Higher Main Group(VI)-Centered Radicals to Alkynes. 2.4 Cascade Reactions Initiated by Addition of Higher Main Group(VI)-Centered Radicals to Alkynes. 2.5 Cascade Reactions Initiated by Addition of Higher Main Group(V)-Centered Radicals to Alkynes. 3. Radical Cation Fragmentation Reactions in OrganicSynthesis (Alexander J. Poniatowski and Paul E.Floreancig). 3.1 Introduction. 3.2 Electron Transfer-Initiated Cyclization Reactions. 3.3 Oxidative Acyliminium Ion Formation. 3.4 Carbon Carbon Bond Formation. 3.5 Summary and Outlook. 4. Selectivity in Radical Cation Cycloadditions (ChristoS. Sevov and Olaf Wiest). 4.1 Introduction. 4.2 Mechanism and the Origin of the Rate Acceleration. 4.3 Selectivity in Radical Cation Cycloadditions. 4.4 Chemoselectivity. 4.5 Regioselectivity. 4.6 Periselectivity. 4.7 Endo/Exo Selectivity. 4.8 Conclusions. 5. The Stability of Carbon-Centered Radicals (Michelle L.Coote, Ching Yeh Lin, and Hendrik Zipse). 5.1 Introduction. 5.2 Theoretical Methods. 5.3 RSE Values for Carbon-Centered Radicals. 5.4 Use of RSE Values in Practical Applications. 5.5 Conclusions. 6. Interplay of Stereoelectronic Vibrational andEnvironmental Effects in Tuning Physicochemical Properties ofCarbon-Centered Radicals (Vincenzo Barone, Malgorzata Biczysko,and Paola Cimino). 6.1 Introduction. 6.2 EPR Spectroscopy. 6.3 Calculation of EPR Parameters. 6.4 Vibrational Properties Beyond the HarmonicApproximation. 6.5 Electronic Properties: Vertical Excitation Energies,Structure, and Frequencies in Excited Electronic States. 6.6 Vibronic Spectra. 6.7 Concluding Remarks. 7. Unusual Structures of Radical Ions in Carbon Skeletons:Nonstandard Chemical Bonding by Restricting Geometries (GeorgGescheidt). 7.1 Introduction. 7.2 The Tools. 7.3 Pagodane and Its Derivatives. 7.4 Different Stages of Cycloaddition/Cycloreversion ReactionsWithin Confined Environments. 7.5 Extending the Cage Concept . 7.6 Summary. 8. Magnetic Field Effects on Radical Pairs in HomogeneousSolution (Jonathan. R. Woodward). 8.1 Introduction. 8.2 The Spin-Correlated Radical Pair. 8.3 Application of a Magnetic Field. 8.4 Spin-State Mixing. 8.5 The Magnetic Field Dependence of Radical PairReactions. 8.6 Theoretical Approaches. 8.7 Experimental Approaches. 8.8 The Life Cycle of Radical Pairs in Homogeneous Solution. 8.9 Summary. 9. Chemical Transformations Within the Paramagnetic WorldInvestigated by Photo-CIDNP (Martin Goez). 9.1 Introduction. 9.2 CIDNP Theory. 9.3 Experimental Methods. 9.4 Radical Radical Transformations During DiffusiveExcursions. 9.5 Radical Radical Transformations at Reencounters. 9.6 Interconversions of Biradicals. 9.7 Conclusions. 10. Spin Relaxation in Ru-Chromophore-LinkedAzine/Diquat Radical Pairs (Matthew T. Rawls, Ilya Kuprov, C.Michael Elliott, and Ulrich E. Steiner). 10.1 Introduction. 10.2 EPR for the Isolated Ions. 10.3 Calculation Methods for EPR of the Isolated Ions. 10.4 Implications for Spin-Relaxation in Linked RadicalPairs. 11. Reaction Dynamics of Carbon-Centered Radicals in ExtremeEnvironments Studied by the Crossed Molecular Beam Technique(Ralf I. Kaiser). 11.1 Introduction. 11.2 The Crossed Molecular Beam Method. 11.3 Experimental Setup. 11.4 Crossed Beam Studies. 11.5 Conclusions. 12. Laser Flash Photolysis of Photoinitiators: ESR, Optical,and IR Spectroscopy Detection of Transients (Igor V. Khudyakovand Nicholas J. Turro). 12.1 Introduction. 12.2 Photodissociation of Initiators. 12.3 TR ESR Detection of Transients. 12.4 Optical Detection of Transients. 12.5 IR Detection of Free Radicals and Monitoring TheirReactions. 12.6 Concluding Remarks. 13. Dynamics of Radical Pair Processes in Bulk Polymers(Carlos A. Chesta and Richard G. Weiss). 13.1 Introduction. 13.2 Singlet-State Radical Pairs from Irradiation of Aryl Estersand Alkyl Aryl Ethers. 13.2.1 General Mechanistic Considerations From Solution andGas-Phase Studies. 13.3 Photo-Reactions of Aryl Esters in Polymer Matrices. KineticInformation from Constant Intensity Irradiations. 13.4 Rate Information from Constant Intensity Irradiation ofAlkyl Aryl Ethers. 13.5 Comparison of Calculated Rates to Other Methods forPolyethylene Films. 13.6 Triplet-State Radical Pairs. 13.7 Concluding Remarks. 14. Acrylic Polymer Radicals: Structural Characterization andDynamics (Malcolm D. E. Forbes and Natalia V. Lebedeva). 14.1 Introduction. 14.2 The Photodegradation Mechanism. 14.3 Polymer Structures. 14.4 The Time-Resolved EPR Experiment. 14.5 Tacticity and Temperature Dependence of AcrylateRadicals. 14.6 Structural Dependence. 14.7 Oxo-Acyl Radicals. 14.8 Spin Polarization Mechanisms. 14.9 Solvent Effects. 14.10 Dynamic Effects. 14.11 Conclusions. Index.