Role of Temperature on Framework Dimensionality: Supramolecular Isomers of Zn3(RCOO)8 Based Metal Organic Frameworks

Three new anionic metal organic frameworks, [Zn-1.5(FDA)(2)(Me2NH2)]center dot xG (1), [Zn-3(FDA)(4)(Me2NH2)(2)]center dot xG (2), and [Zn-1.5(FDA)(2)(Me2NH2)]center dot xG (3) (FDAH(2) = 2,5-furandicarboxylic acid, G = guest), were synthesized solvothermally via a temperature tuning strategy. Compound 1, synthesized at 90 degrees C, has a two-dimensional (2D) sheet structure, while 2 and 3, synthesized at 120 and 160 degrees C, respectively, have three-dimensional (3D) structures. Compound 2 has alternating hydrophobic and hydrophilic channels with pore dimensions similar to 4.3 X 4.4 angstrom(2) and similar to 5.6 X 6.2 angstrom(2), respectively. Compound 3 has only one type of pore with dimensions of similar to 5.3 x 6.2 angstrom(2). All three compounds have eight connected Zn3(RC00)8 nodes as building units and are anionic,.with dimethyl ammonium cations present inside the channels to balance charge. Compounds 1, 2, and 3 are supramolecular isomers with general formula [Zn-1.5(FDA)(2)(Me2NH2)](n).