Syntheses, Characterizations, and Properties of Six Metal−Organic Complexes Based on Flexible Ligand 5-(4-Pyridyl)-methoxyl Isophthalic Acid

Abstract

Six new metal−organic frameworks have been synthesized under hydrothermal conditions, in H2O or DMF/H2O, namely, [CoL]n (1), [Ni2L2(H2O)3]n (2), [CoL(bimx)1/2]n (3), [NiL(bimx)1/2]n (4), [MnL(bimx)1/2]n (5), {[CoL2(bimb)(H2O)2]·2H2O}n (6) (bimx =1,4-bis(imidazol-1-ylmethyl)benzene, bimb =4,4′-bis(imidazol-1-ylmethyl)biphenyl, H2L = 5-(4-pyridyl)-methoxyl isophthalic acid). These complexes were characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Complex 1 reveals a 2-fold interpenetrating three-dimensional (3D) framework with rutile {4 · 62}2{42 . 610 . 83} topology. Complex 2 possesses a 3D 4-fold interpenetrating framework with ths topology. In complexes 3, 4 and 5, H2L and bimx ligands link Co, Ni and Mn cations to generate 3D frameworks. Compound 6 possesses a 3D interlocked structure, with 2D structures intercatenating each other into a 3D structure (2D + 2D→3D) and with new topology. In addition, thermal stabilities, photochemical properties, and the magnetic properties for 1, 3, 4, and 5 are also discussed in detail.