Synthesis, structures, and photoluminescent properties of two ligand unsupported silver(i) coordination polymers from isonicotinate anions

Assembly of isonicotinate acid (HL) and Ag(I) by a layer-separating diffusion method at ambient temperature gave rise to two novel structural coordination polymers with ligand unsupported Ag⋯Ag interactions, namely, [(Ag4L4)·H2O·0.5CH3OH]n (1) and [(Ag3L2)NO3]n (2). Compound 1 is the first example of double-layer architecture and features an alternative stacking mode with Ag⋯Ag interactions, π–π interactions and Ag⋯O interactions. The synthesis of compound 2 offered us an opportunity to study the role of counteranions in Ag⋯Ag interactions. Both compounds display intense room temperature photoluminescence in the solid state.