The anhydride route to group 15/16 ligands in oligomeric and polymeric environments: From metal complexes to supraionic chemistry

The aim of this paper is to introduce a synthetic concept suitable for the preparation of a broad variety of compounds. The so-called anhydride route (in this article the term anhydride is used for compounds derived from corresponding acids by formal loss of H₂O, H₂S and H₂Se) has so far led to a range of unusual Group 15/16 ligands in oligomeric and polymeric environments. Commonly, reactions of neutral precursor molecules, for example, [{RP(S)μ-S)}₂] (R = 4-anisyl) Lawesson's reagent or [{PhP(Se)μ-Se)J₂] Woollins's reagent and metal salts are performed to result in novel coordination compounds in which ligands and metal atoms form coordination oligomers and polymers. An attempt is made to relate the outcome of the investigations to the type of metal used. By relating the strength of ionic interactions, which correspond to metal-donor distances, to phenomena observed in the solid-state structures, an aspect of supraionic chemistry is described. Chemistry of and beyond novel Group 15/16 anions is further discussed using a novel approach in coordination chemistry where the chemical nature of ligands is unknown prior to the experiment despite the use of a range of similar starting materials.