Lithium aspirinate hemihydrate

The title compound {systematic name: catena-poly[lithium(I)-μ₃-acetyl­salicylato-hemi-μ₂-aqua]}, {[Li(C₉H₇O₄)]·0.5H₂O}_n, is the hemihydrate of the lithium salt of aspirin. The carboxyl­ate groups and water mol­ecules bridge between Li atoms to form a one-dimensional coordination chain composed of two distinct ring types. The water O atom lies on a twofold axis. Hydrogen bonding between water donors and carbonyl acceptors further links the coordination chains to form a sheet structure.