Metal–organic frameworks constructed from mixed-ligand1,2,3,4-tetra-(4-pyridyl)-butane and benzene-polycarboxylate acids: syntheses, structures and physical properties

Abstract

Three novel coordination polymers, [Mn(TPB)_0.5(IPA)(H₂O)₂]n (1), [Zn_1.5(TPB)_0.5(TMA)(H₂O)·(H₂O)]n (2), and [Co(TPB)_0.5(PMA)_0.5(H₂O)₂·(H₂O)]n (3) (TPB = 1,2,3,4-tetra-(4-pyridyl)-butane; H₂IPA = isophthalic acid; H₃TMA = trimesic acid; and H₄PMA = pyromellitic acid), have been synthesized under hydrothermal conditions and structurally characterized. Complex 1 features a 2D infinite layer framework consisting of bi-manganese clusters, which is further stacked along the [11] direction via strong interlayer π⋯π interactions to form a 3D supramolecular architecture. Complex 2 has a 3D complicated framework comprised of two kinds of infinite 1D chains. The 3D framework of complex 3 possesses three topologically nonequivalent 4-connected nodes synchronously and exhibits an unprecedented (6⁴·10²)(4²·8⁴)(4·6⁵)₂ topology. The magnetic susceptibility data of complex 1 show strong antiferromagnetic interactions in the dinuclear Mn(II) units. Complex 2 exhibits strong fluorescent emissions in the solid state at room temperature and may be suitable as a candidate of blue-fluorescent material.