The Positive Muon as a Probe in Free Radical Chemistry

1 Introduction.- 1.1 Motivation.- 1.2 History and properties of the muon and its bound states.- 1.3 The muon as a probe in matter.- 2 Experiments employing muons.- 2.1 Muon production and decay.- 2.2 The ?SR techniques.- 2.3 Analysis and interpretation of the data.- 3 Theory.- 3.1 Hamiltonians, eigenvectors and energies.- 3.2 Evolution of spin polarization.- 4 The cyclohexadienyl radical.- 4.1 Observation in the liquid phase.- 4.2 Observation in other phases.- 4.3 Structure and hyperfine couplings.- 5 Substituent effects on hyperfine coupling constants.- 5.1 Monosubstituted radicals.- 5.2 Comparison with data for benzyl.- 5.3 Polysubstituted radicals.- 6 The process of radical formation.- 6.1 Routes to the cyclohexadienyl radical.- 6.2 Radical formation in cyclohexane solution.- 6.3 Selectivity in mixtures of benzene and dimethylbutadiene.- 6.4 Scavenging experiments.- 7 Distribution of muons in substituted benzenes.- 7.1 Monosubstituted benzenes.- 7.2 Polysubstituted benzenes.- 8 Radical reactions.- 8.1 Secondary isotope effects.- 8.2 Electron transfer reactions.- 8.3 Abstraction reactions.- 8.4 Spin exchange reactions.- 8.5 Transfer of bound Mu, an example for a primary kinetic isotope effect.- 9 Summary and review.- 9.1 Objective.- 9.2 The requirements for the observation of muonated radicals.- 9.3 The different types of radicals observed in liquids.- 9.4 Observations in other phases.- 9.5 Investigation of isotope effects.- 9.6 Investigation of early events.- 9.7 Investigation of radical kinetics.- 9.8 Conclusion.