Discrete (carbon free) chelate rings derived from sodium tetraphenylimidodiphosphinochalcogenides (S and Se) and 15-crown-5

Sodium tetraphenylimidodiphosphinochalcogenide salts Na[(Ph2P(X)NP(X)Ph2)] (X = S, Se), react with 15-crown-5 ether to give two complexes [Na(15C5)][(Ph2P(X)NP(X)Ph2)] (X = S, Se), 1 and 2 respectively. The crystal and molecular structures of the resulting compounds were determined by X-ray diffractometry. The compounds are isostructural showing sodium–sulfur and sodium–selenium interactions, respectively, forming discrete inorganic (carbon free) chelate rings. These are different from the complex from the oxygen homolog which is an aggregated poly-ion, containing sodium ions with different coordination environments.