Paramagnetic spectroscopy of vanadyl complexes and its applications to biological systems

The ability to determine the ligand environment around vanadium(IV), usually as the vanadyl ion (VO2+), has become crucial to the understanding of many biological systems. In addition to those systems in which vanadium naturally occurs, the vanadyl ion has found favor as a spectroscopic probe in place of spectroscopically silent cations, EPR, ESEEM, and ENDOR spectroscopies are the tools of choice for examining these paramagnetic systems. A variety of model complex studies allow good comparisons to be made to known vanadium environments. The complimentary nature of the strengths and weaknesses of these techniques can combine to give an accurate picture of the metal ligation in a number of cases herein. (C) 2002 Published by Elsevier Science B.V.