Two novel luminescent silver(I) coordination polymers containing octanuclear silver cluster units or ligand unsupported Ag⋯Ag interactions constructed from 5-sulfoisophthalic acid (H3SIP) and organic amine

Self-assembly of Ag(NO3)2 with 5-sulfoisophthalic acid monosodium salt (NaH2SIP) in the presence of piperazine (pip) or 4,4′-bipyridyl (bpy) produced two new silver(I) coordination polymers, {(H2pip)2[Ag8(SIP)4(H2O)4](H2O)4}n (1) and {[Ag(bpy)][Ag(HSIP)(bpy)](H2O)2}n (2), respectively. Single-crystal X-ray diffraction reveals that compound 1 has a 2D silver carboxylate-sulfonate layered structure containing an uncommon octanuclear [Ag8(CO2)8] cluster wherein the eight silver(I) atoms form two intersecting Ag4 planes. The 2D layers are further linked by the H2pip molecules through hydrogen bonds into a 3D supramolecular structure. Compound 2 features a 2D supramolecular network formed by silver(I)-bpy double chains and HSIP ligands through the combination of coordination bonds, ligand unsupported Ag⋯Ag interactions and weak Ag⋯O coordinative interactions. In the solid state at room temperature, compound 1 exhibits blue photoluminescence with a maximum at 450 nm upon excitation at 365 nm. Compound 2 shows green photoluminescence with a maximum at 564 nm upon excitation at 392 nm.