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Inhaltsverzeichnis

Frontmatter

1. The Basic Physics of Spin-1 Systems

Abstract
In the following, we present a simple theory toolkit that is useful to compute the response of spin-1 systems to a variety of NMR experiments that are discussed in the two subsequent Chapters. The emphasis is on developing the relevant tools, instead of a formal treatment of the theory of spin-1 angular momentum. Following a general introduction to the problem at hand, we start with a quick and simple Summary of relevant aspects of spin-1 angular momentum theory, introducing a Hermitian, Cartesian operator basis, its matrix representation in two different eigenbases, and the Commutator algebra for spin-1. This is followed by a projection operator treatment of functions of Hermitian spin-1 operators, which is employed to build up an explicit matrix representation of rotations, effected for instance by hard pulses. The interactions relevant in spin-1 NMR are briefly discussed, followed by an introduction to the density matrix description of the state of spin-1 ensembles. This provides the background to evaluate evolution of spin-1 systems under various interactions, including quadrupolar coupling, scalar coupling to spin-1/2 and scalar coupling to spin-1. The rotation behavior of spin-1 wavefunctions is discussed both for selective two-level excitation (in the presence of quadrupolar coupling), as well as for non-selective three-level excitation, the latter in solution state. A simple coherence transfer function for weakly coupled systems of N inequivalent spins-1 is given next, based on the rotation matrix previously introduced. Finally, a brief treatment of quadrupolar relaxation in spin-1 systems is given, the emphasis once again being the derivation of relevant relaxation rates.
Narayanan Chandrakumar

2. NMR of Systems Involving Spin-1 Nuclei in the Isotropic Phase

Abstract
In this Section, we give an account of solution state NMR experiments involving spin-1 isotopes, with emphasis on approaches to chemical problem solving and structure elucidation. It is to be noted that solution state NMR involving these quadrupolar nuclei is still often of the high resolution category, owing to the averaging out of quadrupolar interactions in isotropic phase by virtue of the rapid random tumbling of molecules. This feature has been exploited extensively in recent years with the optimization and implementation of a variety of complex spin orchestrations. We begin with a brief discussion of the usefulness of isotope substitution/enrichment strategies in eliciting information on molecular structure, pointing to the fields of non-classical hydrides, lithium cluster size determination and site-specific natural isotope fraction.
Narayanan Chandrakumar

3. NMR of Spin-1 Systems in the Solid State

Abstract
In this section, we discuss the NMR of spin-1 systems in the solid state. Following a brief introductory survey of the field, simple theoretical treatments of the Quadrupolar Echo sequence and the Jeener-Broekaert sequence are given, employing the Cartesian single-spin operator representation. The experiments that are then treated include deuterium NMR spectroscopy of single crystal systems, 2D deuterium COSY in the solid state, 2H NMR under MAS, Double Quantum Spectroscopy, QUADSHIFT, Overtone Spectroscopy, Spin-1/2-Spin-1 dipolar couplings in spin-1/2 CP/MAS work, spin alignment, deuterium exchange spectroscopy and 2H double quantum imaging. Finally, the Chapter concludes with a Section on the Instrumentation requirements for solid state spin-1 NMR.
Narayanan Chandrakumar

Backmatter

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