Structures of alkali metal salts with [W(CN)6(bpy)]− ion. Comparative studies to W(IV) analogues

• Published in: Polyhedron 2021-10, Vol.207, p.115369, Article 115369
• Main Authors: Hodorowicz, Maciej, Jurowska, Anna, Szklarzewicz, Janusz
• Format: Article
• Language: English
• Subjects: 2,2′-bipyridyl; Alkali metal salts; Crystal structure; Hexacyanido; Tungsten
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2021.115369

Na, K and Rb salts with the [W(CN)6(bpy)]− ion were synthesized and their structures were compared to W(IV) analogues. The changes in a spatial arrangement of the structures are discussed. [Display omitted] Three complexes with the formula Na[W(CN)6(bpy)]·H2O (1), K[W(CN)6(bpy)] (2) and Rb[W(CN)6(bpy)] (3) have been synthesized and structurally characterized based on the X-ray analysis of single crystals, as well as described and compared with analogues in which the tungsten atom is in the fourth oxidation state. All salts crystallize in orthorhombic (Pbca for 1) or monoclinic (P21/c for 2 and 3) space groups. Contrary to the layered systems containing the negative anionic complexes of W(IV), the compounds described in the publication containing the negative anionic complexes of W(V) form much more complex structural systems, the arrangement of which is based on an extensive network of bridging cyanido ligands. This network is additionally stabilized by π-π type interactions of bipyridyl ligands. This phenomenon of a different spatial arrangement of the structure in the studied compounds compared to the layered W(IV) systems is surprising and proves that the structure of the bridge cyanido systems is influenced by many, previously unpredictable factors, and the knowledge of crystal engineering of cyanido polymers itself is not field too vast.