catena-Poly[[[4-amino-3,5-bis(pyridin-2-yl)-4H-1,2,4-triazole-κ²N¹,N⁵](dicyanamido-κN)copper(II)]-μ₂-dicyanamido-κ²N:N′]: coordination polymer chains linked into a bilayer by hydrogen bonds and π–π stacking interactions

Abstract

In the title compound, [Cu(C 2 N 3 ) 2 (C 12 H 10 N 6 )] n or [Cu(dca) 2 -(abpt)] n , where abpt is 4-amino-3,5-bis(pyridin-2-yl)-4H-1,2,4-triazole and dca is the dicyanamide anion, the Cu II centre is five-coordinate with an approximately square-pyramidal geometry. One of the two dicyanamide ligands is a terminal ligand, but the other one acts as a 1,5 -bridging ligand between pairs of Cu II centres, so generating a one-dimensional coordination polymer. A combination of N-HÁ Á ÁN and C-HÁ Á ÁN hydrogen bonds, augmented by -stacking interactions, links the coordination polymer chains into a bilayer structure. Comparisons are made with some related Cu II complexes containing dca ligands and heteroaromatic coligands.

Three zinc(II) and cadmium(II) complexes containing 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole and polynitrile ligands: synthesis, molecular and supramolecular structures, and photoluminescence properties

“…There is thus no scope for the anionic ligands to exhibit any bridging behaviour between pairs of metal centres. Such behaviour is however observed, for example, in [Cu(dca) 2 (abpt)], where one of the dca ligands is monodentate, while the other acts as a bridging ligand between adjacent five-coordinate, approximately squarepyramidal, Cu II centres in a one-dimensional coordination polymer, in which the CuÁ Á ÁCu separation along the chain is 7.5946 (5) Å (Setifi, Setifi, Saadi et al, 2014), and in [CdCl-(dca) 2 L 0 ], where L 0 represents 3,5-dimethyl-1-(pyridin-2-yl)pyrazole, in which both dca ligands act as bridging ligands between adjacent [Cd 2 Cl 2 L 0 2 ] units, forming a one-dimensional coordination polymer in which four-and twelvemembered rings alternate (Das et al, 2013).…”