Bis(7-amino-1,2,4-triazolo[1,5-a]pyrimidin-4-ium) bis-(oxalato-κO,O)cuprate(II) dihydrate.

ABSTRACT

The structure of the title ionic compound, (C(5)H(6)N(5))(2)[Cu(C(2)O(4))(2)]·2H(2)O, consists of a centrosymmetric copper(II) oxalate dianion, two monoprotonated mol-ecules of the adenine analog 7-amino-1,2,4-triazolo[1,5-a]pyrimidine (7atp) and two water mol-ecules of crystallization. The Cu(II) ion, located on an inversion center, exhibits a sligthly distorted square-planar coordination geometry, in which two oxalate anions bind in a bidentate fashion. The triazolopyrimidine ligand is protonated at the N atom in position 4, instead of its most basic N atom in position 3. This fact may be explained by the network stability, which is provided through the formation of a two-dimensional wave-like network parallel to (50[Formula see text]) by N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds. These nets are further connected via C-H⋯O inter-actions.