A new cadmium coordination polymer based on 4-amino-4H-1,2,4-triazole.

Maha Said,Habib Boughzala

doi:10.1107/s2056989018000464

Abstract

A new cadmium coordination polymer, poly[bis-(4-amino-4H-1,2,4-triazolium) [bis-(μ2-4-amino-4H-1,2,4-triazole-κ2N1:N2)tetra-μ2-chlorido-tetra-chlorido-tri-cad-mium(II)] dihydrate], {(C2H5N4)2[Cd3Cl8(C2H4N4)2]·2H2O} n , was synthesized by the reaction of 4-amino-4H-1,2,4 triazole with cadmium(II) chloride in aqueous solution. With an unusual architecture, the crystal structure exhibits two distorted octa-hedral coordinations of CdII joined by edge sharing. The first is composed by four chlorine and two N atoms from the triazole ligands. The second is formed by five Cl atoms and by one N atom from the triazole ligand. The charge of the resulting two-dimensional anionic framework is balanced by the organic triazole cations. The lattice water mol-ecules form a network of hydrogen bonding. N-H⋯Cl and π-π stacking inter-actions are also involved in the supra-molecular network stability.

Highlights

A new cadmium coordination polymer, poly[bis(4-amino-4H-1,2,4-triazolium) [bis(2-4-amino-4H-1,2,4-triazole-2N1:N2)tetra-2-chlorido-tetrachloridotricadmium(II)] dihydrate], {(C2H5N4)2[Cd3Cl8(C2H4N4)2]Á2H2O}n, was synthesized by the reaction of 4-amino-4H-1,2,4 triazole with cadmium(II) chloride in aqueous solution
The first is composed by four chlorine and two N atoms from the triazole ligands
The second is formed by five Cl atoms and by one N atom from the triazole ligand

Summary

Chemical context

The last decade has seen a large number of investigations of CdII hybrid coordination polymers (HCPs) These materials exhibit a wide variety of polymeric frameworks with attractive properties. The choice of the organic ligands is an important factor that greatly influences the structure and stabilization of the coordination architecture formed (Tao et al, 2000; Choi & Jeon, 2003). In this regard, organic building units that are based on five-membered N-heterocycles such as 1,2,4 triazole exhibit a strong and typical property of acting as bridging ligands between two metal centres. The reaction of 4-amino-4H-1,2,4 triazole (NH2trz) with cadmium dichloride leads to the formation of the title two-dimensional coordination polymer

Structural commentary

Supramolecular features

Database survey

Synthesis and crystallization

Refinement