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

Abstract

The reaction of AgX with the diphosphazane ligand, Pr i N(PPh 2) 2 ( L) gives the polymeric complexes, [Ag 2(μ-X) 2(μ-L)] n (X = NO 3 1a or OSO 2CF 3 1b). 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 ‘ C s’ 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 = NO 3 2a, X = OSO 2CF 3 2b) and [Ag(κ 2-L) 2]X (X = NO 3 3a, X = OSO 2CF 3 3b).