Polyoxometalate-Based Metal−Organic Frameworks Assembled under the Ionothermal Conditions

One new polyoxometalate compound H 3 (Tea)(Bmim) 3 [P 2 W 18 O 62 ]·3H 2 O (Tea = triethylamine, Bmim = 1-methyl-3-ethylimidazole) ( 1 ) and three new polyoxometalate-based metal−organic frameworks (PMOFs) Cu II (Bbi) 1.5 (H 2 Bbi) 2 [P 2 W 18 O 62 ] (Bbi = 1,1-(1,4-butanediyl)-bis(imidazole)) ( 2 ), Cu II 2.5 (Mimin)(HMimin)(Bbi) 3 [P 2 W 18 O 62 ]·3H 2 O (Mimin = methylimidazol) ( 3 ), and Cu II (Bbtz)(H 2 Bbi)(H 2 Btp)[P 2 W 18 O 62 ] (Bbtz = 1,4-bis(triazol-1-ylmethyl)benzene, Btp = 1,3-Bis(1,2,4-triazol-1-yl)propane) ( 4 ) have been synthesized under ionothermal conditions using an ionic liquid (IL) [Bmim]Br (Bmim = 1-ethyl-3-methylimidazole) as solvent. Their structures were determined by single crystal X-ray diffraction. Compound 1 possesses a one-dimensional (1D) supramolecular chain-like structure constructed from [P 2 W 18 O 62 ] 6− anions, Bmim, Tea, and water molecules. Compound 2 has a two-dimensional (2D) (6,3)-layer structure built by [P 2 W 18 O 62 ] 6− anions, copper ions, and Bbi ligands. Compounds 3 and 4 are three-dimensional (3D) PMOFs with novel (6.8.10)(4.6.8 3 .10)(4.6.8 3 .12) and classic (6 5 .8)(6 5 .8)- cds topologies, respectively. Compounds 2 − 4 represent the first examples of PMOFs synthesized by the ionothermal method. The successful synthesis of compounds 2 − 4 suggests that ionothermal synthesis will be a very promising synthetic technique for assembling new PMOFs. Additionally, the properties of the four compounds have been studied in detail.