Moderne methodische Entwicklungen in der Elektronenspinresonanz-Spektroskopie

Abstract

Electron spin resonance ( ESR) is extensively used in various fields of research as a powerful toolfor the determination of molecular structures ofparamagnetic compounds. In particular solid state physics, organic and inorganic chemistry, materials science, biology, and environmental science apply this sensitive and non-destructive spectroscopic technique with great success. However, ESR often suffers from a poor spectral resolution which may severely limit its applicability. The demand for improved resolution in electron spin resonance stimulated the development of various novel experimental techniques. In this review article, we present two modern methods, namely electron nuclear double resonance (ENDOR) and electron spin echo (ESE) spectroscopy. The high resolution inherent in these techniques provides the scientist with a detailed picture of the chemical bonding in paramagnetic species. The basic principles and the state-of-the-art of ENDOR and ESE methodology in solids will be outlined. The scope and the limitations of these advanced magnetic resonance techniques, particularly in coordination chemistry, will be discussed and illustrated by' different examples.