Assembly of 1D, 2D and 3D silver(I) coordination polymers with nitrilotriacetate and 2-aminopyrimidyl mixed ligands

Three mixed ligands coordination polymers (CPs) [Ag1.5(apym)(nta)0.5]n (1), [(NH4)Ag2(mapym)(nta)·(H2O)3]n (2), [Ag2(dmapym)3(Hnta)]n (3) (apym = 2-aminopyrimidine, mapym = 4-methyl-2-aminopyrimidine, dmapym = 4, 6-dimethyl-2-aminopyrimidine, H3nta = nitrilotriacetate) were synthesized and characterized. For 1–3, as the substituents change from H to one methyl and two methyl groups, the dimensionalities of 1–3 decrease from three-dimension (3D) to one-dimension (1D) due to the steric effect of methyl groups. For 1, the μ2-apym ligands link the Ag(I) ions to form a 1D double-chain incorporating ligand unsupported Ag···Ag interaction. The nta3− ligands extend the 1D double-chain into a 3D framework. In 2, one heptadentate nta3− ligand binds four Ag(I) ions and incorporates μ2-mapym ligand to link metal centers to form a 2D sheet which can be simplified to be a 103 net. Complex 3 features a 1D chain structure incorporating Hnta2− and monodentate dmapym ligands. The substituents on the pyrimidyl ring intensively influence the coordination environments of metal ion and the coordination modes of the carboxyl group, and thus determine the structures of the CPs. The photoluminescent properties of 1–3 were also investigated.