From infinite tubular arrays to discrete molecules and back: An example of reversible ring-opening polymerization in silver(I)–diphosphazane chemistry

The reaction of AgX with the diphosphazane ligand, PriN(PPh2)2 (L) gives the polymeric complexes, [Ag2(μ-X)2(μ-L)]n (X = NO31a or OSO2CF31b). Single crystal X-ray analysis of 1a reveals a novel structural motif formed by interlinking of giant 40-membered rings; the diphosphazane ligand L adopts a unique ‘Cs’ geometry. These polymeric complexes exhibit a completely reversible ring-opening polymerization–depolymerization relationship with the dinuclear and mononuclear complexes, [{Ag(μ-L)(X)}2] (X = NO32a, X = OSO2CF32b) and [Ag(κ2-L)2]X (X = NO33a, X = OSO2CF33b).