Crystal structure of meso-di-μ-chlorido-bis-[bis-(2,2'-bi-pyridine)-cadmium] bis-(1,1,3,3-tetra-cyano-2-ethoxy-propenide) 0.81-hydrate

Abstract

The hydrated title salt, [Cd₂Cl₂(C₁₀H₈N₂)₄](C₉H₅N₄O)₂·0.81H₂O, was obtained from the hydro-thermal reaction between 2,2'-bi-pyridine, cadmium(II) chloride and potassium 1,1,3,3-tetra-cyano-2-eth-oxy-propenide. The binuclear cation lies across a centre of inversion in the space group P2₁/c, with the other components in general positions. The cation has approximate, but non-crystallographic 2/m symmetry and each of the Cd^II atoms is a stereogenic centre, one having the Δ configuration and the other the Λ configuration. In the anion, one of the C(CN)₂ units is disordered over two sets of atomic sites having occupancies 0.75 (2) and 0.25 (2). The cations are linked by two independent C-H⋯Cl hydrogen bonds to form a sheet of R₂²(14) and R₄²(24) rings.

Keywords: crystal structure; hydrogen bonding; hydro­thermal synthesis; mol­ecular disorder; mol­ecular structure; polynitrile anions.