Novel synthesis of a potentially trinucleating ligand: 1,3-bis-(2-hydroxyphenyl)-1,3-propanedione

Reaction of 1,3-bis-(2-hydroxyphenyl)-1,3-propanedione (H3L), a ligand with three possible sites of coordination acting as a chelating agent, with metal acetates results in the formation of mononuclear species M(H2L)2·S,S′ (M = Zn, Cu, Co; S,S′ = solvent or water molecules). A compound of general formula NEt4[Li(H2L)2] is obtained upon reaction of Zn(H2L)2·S,S′ with excess of lithium ethanolate. Further reaction of the mononuclear species with excess of the appropriate metal acetate yielded di- or trinuclear complexes depending upon the metal used. Due to the different coordination sites of H3L it is expected that trinuclear complexes of the types A3, A2B or AB2 will be obtained. Examples of the types A3 and A2B are reported. © 1984.