Synthesis and structural characterization of mixed-ligand silver(I) complexes containing diphosphazanes and bidentate N-donor ligands

The reactions of a self-assembled silver(I) coordination polymer, [Ag2{μ-PriN(PPh2)2}(μ-NO3)2 ]n (1) with various bidentate N-donor ligands such as DABCO, 2,2'-bipyridyl and 1,10-phenanthroline yield 1-D helices or π-π stacked polymers, depending on the chelate vector of the N-donor ligand. The molecular structures of the resultant complexes, [Ag2{μ-PriN(PPh2)2}(DABCO)(NO3)2]n (2), [Ag2{μ-PriN(PPh2)2}(2,2'-bipy)2(NO3)2] (3) and [Ag2{μ-PriN(PPh2)2}(1,10-phen)2 ](NO3)2 (4) have been confirmed by single-crystal X-ray diffraction. Complex 2 exists as an infinite helical polymer because of the exo-bidentate nature of DABCO. Complex 3 assumes a 2D grid motif as a result of intermolecular π-π stacking among adjacent bipyridine moieties. The phenanthroline complex 4 exhibits strong inter- and intramolecular π-π stacking interactions