Detection and structural characterization of oxo-chromium(V)–sugar complexes by electron paramagnetic resonance

Abstract

The present review describes the detection and characterization of oxo-Cr(V)-saccharides coordination compounds, produced during chromic oxidation of carbohydrates by Cr(VI) and Cr(V) using electron paramagnetic resonance (EPR) spectroscopy. After an introduction into the main importance of chromium (bio) chemistry and more specifically the oxo-chromium(V) sugar complexes, a general overview is given of the current state-of-the-art EPR techniques. In a next step, it is reviewed which types of EPR spectroscopies are currently applied to oxo-Cr(V) complexes and what information about these systems can be gained from such experiments. The advantages and pitfalls of the different approaches will be discussed and it will be shown that the potential of high-field and pulsed EPR techniques is as yet still largely unexploited in the field of oxo-Cr(V) complexes. In the following part, the discussion is focused on the analysis of oxo-Cr(V) complexes of different kinds of sugars and the implications of the results in terms of understanding chromium (bio)chemistry.