Silver-triphenylphosphine coordination polymers with linear spacer ligands

Abstract

In the presence of PPh3, AgX (X = ClO4 -, I-, NO3 -, CH3CO2 -) and linear spacer ligands 4,4′;-bipyridine (bpy), 1,4-diazobicyclo[2,2,2]octane (dabco) and pyrazine (pyz) react to form [{Ph3PAg}2(μ-bpy)](ClO4)2 (1), [{Ph3PAgI}2(μ-bpy)]n (2), [{(Ph3P)Ag(ONO2)}2(μ-bpy)]n (3), [{Ag(μ-OAc)}2(μ-bpy)2]n.6nH2O (4), [{(Ph3P)Ag(NO3)}2(μ-dabco)]n (5) and [Ag(NO3)(μ-pyz)]n (6). The structures of 1-4 were determined by X-ray crystallography. Compound 1 contains a binuclear cation and two ClO4 - anions with very weak interactions between silver and ClO4 - anions, whereas 2 and 3 are stair-step undulating polymer chains. A ladder type of structure was observed in 4 in which two of the [Ag(μ-bpy)]n linear chains are bridged by two acetate ligands and paired by Ag..Ag interactions of 3.1347(8) angstroms and π-π interactions of 3.67-3.63 angstroms.