Experimental methods employing spin resonance effects (nuclear magnetic resonance and electron spin resonance) are broadly used in molecular science due to their unique potential to reveal mechanisms of molecular motion, structure, and interactions. The developed techniques bring together biologists investigating dynamics of proteins, material science researchers looking for better electrolytes, or nanotechnology scientists inquiring into dynamics of nano-objects. Nevertheless, one can profit from the rich source of information provided by spin resonance methods only when appropriate theoretical models are available. The obtained experimental results reflect intertwined quantum–mechanical and dynamical properties of molecular systems, and to interpret them one has to first understand the quantum–mechanical principles of the underlying processes.
This book concentrates on the theory of spin resonance phenomena and the relaxation theory, which have been discussed from first principles to introduce the reader to the language of quantum mechanics used to describe the behaviour of atomic nuclei and electrons. There is a long way from knowing complex formulae to apply them correctly to describe the studied system. The book shows through examples how symbols can be "replaced" in equations by using properties of real systems to formulate descriptions that link the quantities observed in spin resonance experiments with dynamics and structure of molecules.
Preface
Classical description of spin resonance
Larmor precession and Bloch equations
Introduction to spin relaxation
The nature of relaxation processes
Correlation functions and spectral densities
The simplest relaxation formula
Bi-exponential relaxation
Formal theory of spin relaxation
The concept of density operator
The Liouville von Neumann equation and relaxation rates
Liouville space and Redfield kite
Validity range of the perturbation theory
Spin relaxation in time domain
Spin resonance lineshape analysis
The concept of spin resonance spectrum
Spin resonance spectrum and motion
Examples of spin resonance spectra
Rigid spectra and the lineshape theory
Spin resonance spectra and correlation functions
Spin relaxation – a more general approach
Generalized spectral densities
Residual dipolar interactions
Interference effects
Cross-correlation effects
Hierarchy of spin relaxation processes
Electron spin resonances of spins 1/2
ESR spectra and scalar interactions for 15N systems
ESR spectra and scalar interactions for 14N systems
ESR spectra at low frequencies
g - tensor anisotropy
Nuclear spin relaxation in paramagnetic liquids
Proton relaxation and hyperfine coupling
Translational dynamics in paramagnetic liquids
Effects of electron spin relaxation
Hilbert space and spin relaxation
Spin resonance beyond perturbation range
Intermediate spin resonance spectra
Stochastic Liouville formalism
2H NMR spectroscopy and motional heterogeneity
2H NMR spectroscopy and mechanism of motion
Deviations from perturbation approach
Dipolar relaxation and quadrupolar interactions
Quadrupole relaxation enhancement (QRE)
Perturbation approach to Quadrupole Relaxation Enhancement
Polarization transfer
QRE and internal dynamics of molecules
Effects of mutual spin interactions
ESR spectra for interacting paramagnetic centres
Interference effects for nitroxide radicals
Spin interactions and molecular geometry
Dynamic Nuclear Polarization
Principles of Dynamic Nuclear Polarization (DNP)
DNP and ESR Spectrum
Anisotropic and Internal Dynamics
Anisotropic rotation
Internal dynamics
Index
Biography
Danuta Kruk is associate professor at the Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Poland. She received her master’s and doctorate degrees in physics as well as attained her habilitation from the Jagiellonian University, Krakow, Poland. She has also been associated with Physical Chemistry Arrhenius Laboratory, Stockholm University, Sweden; Faculty of Physics, Technical University Darmstadt, Germany; and Experimentalphysik, University of Bayreuth, Germany. She is author of the book Theory of Evolution and Relaxation of Multi-Spin Systems. Her current research interests are theory of spin resonances and relaxation processes, dynamics of condensed matter including molecular and ionic liquids, polymers and biological macromolecules, spin relaxation in paramagnetic and superparamagnetic systems, transport phenomena and dynamics of electrolytes and nanofluids, and dynamical properties of solids.
