Spacer-directed coordination polymers-of-oligomers (POLO) of silver.

A novel series of Ag(I) polymers-of-oligomers with pyridylcarboxylate spacers supported by a diphosphine [1,1'-bis(diphenylphosphino)methane (dppm) or 1,1'-bis(diphenylphosphino)ferrocene (dppf)] has been constructed and crystallographically established. The repeating oligomeric Ag5 block is invariably made up of five Ag(I) centers comprising Ag2 and Ag units with different metal geometries. Other related Ag5 and Ag4 assemblies have also been isolated. The preparation of the [Ag2(isonic)(dppm)2]n(n+) polymer (isonic = 4-pyridyl formate, NC5H4CO2(-)) using a ligand transfer pathway from NiCl2(dppm) to AgOTf (OTf = CF3SO3(-)) has been identified. The structural outcomes suggested that pyridylcarboxylates of different stereogeometrical and conformational properties can stabilize different oligomeric and topological forms through adaptation to the contrasting demands of the diphosphine and metal.