IONIC RECOGNITION BY 7 NITRO 1,3,5 TRIAZA ADAMANTANE: FIRST THERMODYNAMIC STUDY

A. F. DANIL DE NAMOR; N. A. NWOGU; J. A. ZVIETCOVICH-GUERRA; O. E. PIRO; E. E. CASTELLANO

JOURNAL OF CHEMICAL PHYSICS

American Chemical Society

Año: 2009 vol. 113 p. 4775 - 4780

0021-9606

A thermodynamic study involving 7-nitro-1,3,5-triaza aza adamantane, 1 and its interaction with metal cations in non aqueous media is first reported. Thus solubility data of 1 in various solvents were used to derive the standard Gibbs energies of solution, ∆sGo  in these solvents. The effect of solvation in the different media was assessed from the Gibbs energy of transfer taking acetonitrile as a reference solvent. 1H NMR studies of the interaction of 1 and metal cations were carried out in CD3CN and CD3OD and the data are reported. Conductance measurements revealed that this ligand interacts with either lead (II) or zinc forming complexes of 1:1 stoichiometry in acetonitrile. However, two molecules of 1 interact with one unit of mercury (II) while two units of cadmium (II) are taken up per unit of 1. The composition of mercury (II) complex in acetonitrile was also observed in solid state (X ray diffraction studies). The addition of silver salt to 1 led to the precipitation of the silver-1 complex which was isolated and characterized by X ray crystallography. The thermodynamics of complexation of 1 and these cations provide a quantitative assessment of the selective behavour of this ligand for ions of environmental relevance.