Table of Contents
Metal-Based Drugs
Volume 2, Issue 2, Pages 105-110

Structural Characterization of the Rhenium(V) Oxo Complex of Mercaptoacetyltriglyclne in its Dianionic Form

1Emory University, Department of Radiology, Atlanta 30322, Georgia, USA
2Emory University, Department of Chemistry, Atlanta 30322, Georgia, USA

Received 2 December 1994; Accepted 10 January 1995

Copyright © 1995 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Dianionic [MO(MAG3)]2(MAG3= penta-anionic form of mercaptoacetyltriglycine, M = R186e,T99mc ) complexes have important applications in nuclear medicine. In vivo the complexes have a deprotonated carboxyl group that is important to their biodistribution. The solid-state structures of T99c and Re complexes with mercaptoacetyltriglycine reported previously are monoanions with protonated carboxyl groups. In the present work, we report the preparation and X-ray crystal structure of Na2[ReO(MAG3)]·5H2O(1), which contains the physiologically relevant dianion. The dianion is a distorted square pyramid with the nitrogen and sulphur donor atoms forming the base and the oxo ligand at the apex. The terminal carboxyl group is deprotonated, uncoordinated and has a syn orientation with respect to the oxo ligand. The syn conformation of the dianion in 1 differs in conformation from the anti-monoanion in [Bu4N][ReO(MAG3H)] but is similar to the syn-monoanion in [Ph4P][T99cO(MAG3H)] .