Table of Contents
International Journal of Inorganic Chemistry
Volume 2014, Article ID 397132, 9 pages
Research Article

Solution Studies on Co(II), Ni(II), Cu(II), and Zn(II) Complexes of Hexamethylenetetramine in Aqueous and Non-Aqueous Solvents

1Department of Inorganic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
2Institut de Chimie Moléculaire de Reims (ICMR), UMR CNRS 7312, Université de Reims Champagne-Ardenne, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
3Département de Chimie, Faculté des Sciences, Université de Douala, Douala, Cameroon

Received 27 August 2013; Revised 16 December 2013; Accepted 17 December 2013; Published 3 March 2014

Academic Editor: Alfonso Castiñeiras

Copyright © 2014 Awawou G. Paboudam et al. 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.


Potentiometric studies in aqueous medium and spectrophotometric study in non-aqueous medium were used to understand the behavior of hexamethylenetetramine (HMTA) complexes. The protometric studies of HMTA enabled us to confirm that only one basic site of this ligand is protonated in acidic medium and this ligand is decomposed in acidic medium. In aqueous medium, only hexa-aqua complexes in which HMTA is present in the second coordination sphere forming H-bonds with hydrogen atoms of coordinated and uncoordinated water molecules are obtained. In non-aqueous solvents, HMTA coordinates to metal ions displaying diversity in the structures of the resulting complexes in which HMTA can either be monodentate, bridged bidentate, tridentate, or tetradentate.