A novel Co(II) metal-organic framework based on 6-methylpyridine-2,4- dicarboxylic acid n-oxide: Synthesis, crystal structure and thermal stability

摘要

A novel metal-organic framework based on 6-methylpyridine-2,4-dicarboxylic acid N-oxide (MPDCO) ligand, [Co(MPDCO)(bix)_(0.5)(H_2O) _2] _n (bix = 1,4-bis(imidazol-1-ylmethyl)-benzene), has been prepared and structurally characterized. Single crystal X-ray analysis shows that it crystallizes in the monoclinic space group of P2_1 with four independent lattice parameters a = 10.269(2) ?, b = 10.462(2) ?, c = 15.875(4) ?, and β = 107.657(4)°, and it has four independent molecules in the unit cell (Z = 4). A one-dimensional (1-D) helical chain was formed through the MPDCO spacer and Co~(2+) centers along the a-axis. Then, these 1-D chains were further interconnected by the bidentate ligand bix to afford an infinite puckered 2-D herringbone framework with (6,3) topology. And a 3-D supramolecular network was formed through the strong intermolecular hydrogen bonds. Graphical Abstract: A two-dimensional Co(II) metal-organic framework constructed from the mixed ligands 6-methylpyridine-2,4- dicarboxylic acid N-oxide (MPDCO) and 1,4-bis(imidazol-1-ylmethyl)-benzene (bix) was synthesized and characterized.[Figure not available: see fulltext.]