Table of Contents
Journal of Crystallography
Volume 2013, Article ID 741483, 5 pages
Research Article

Bis(ammonium) Zoledronate Dihydrate

Department of Chemistry, Gdańsk University of Technology, G. Narutowicza 11/12, 80233 Gdańsk, Poland

Received 23 April 2013; Accepted 27 August 2013

Academic Editors: M. Du, P. Macchi, and Y. Xu

Copyright © 2013 Małgorzata Sikorska and Jarosław Chojnacki. 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.


Neutralization of 2-(1-imidazole)-1-hydroxyl-1,1′-ethylidenediphosphonic acid (zoledronic acid) by an excess of ammonia yielded bis(ammonium) zoledronate dihydrate, { , 2(H4N+), 2(H2O)}. The product is readily soluble in water and forms monocrystals for which the X-ray structural analysis was carried out. The zoledronic anion is of double negative charge due to deprotonation of three P–OH groups and protonation of the nitrogen in the imidazole ring. The structure is stabilized by extensive network of N–HO and O–HO hydrogen bonds expanding through the crystal in plane (002). The imidazole ring is involved in - stacking interactions with its symmetry equivalents related by inversion centers at (100) and (11/20), with distances between centroids (Cg–Cg) of 3.819 (2) and 3.881 (2) Å, respectively.