Ionothermal synthesis of a metal-organic framework constructed by magnesium(II) and 4,4′-oxybis(benzoic acid) ligand

By using the ionic liquid 1-butyl-2,3-dimethylimidazolium bromide ([Bmmim]Br) as solvent and reactant, a magnesium(II) metal complex, namely, [Bmmim][Mg3(oba)3(obaH)] (1) (obaH2 = 4,4′-oxybis(benzoic acid)) has been synthesized ionothermally, which represents the first Mg(II)-oba metal-organic framework. Single-crystal X-ray analysis indicated that the structure of 1 featured a three-dimensionally anionic framework of [Mg3(oba)3(obaH)]nn−. Photoluminescence measurements revealed that 1 exhibited strong emission at 387 nm ascribed to ligand-to-metal charge transfer.