Synthesis, structure, and magnetic properties of manganese-organic frameworks of 2-methyl-4,4′-biphenyldicarboxylate with different auxiliary ligands

Three new metal organic frameworks, [Mn(mbpdc)(phen)](n) (1), [Mn(mbpdc)(4,4'-bipy)](n) (2) and [Mn(mbpdc)(bpee)](n)center dot nC(2)H(5)OH (3) (H(2)mbpdc = 2-methyl-4,4'-biphenyldicarboxylicacid, phen = 1,10-phenanthroline, and bpee = 1,2-Di(4-pyridyl)ethane), have been synthesized by the liquid phase diffusion method and characterized by single crystal X-ray determination and infrared spectra. Compounds 1 and 2 are characterized by elemental analysis, powder X-ray diffraction and thermogravimetric analysis. Compounds 1 and 2 both feature 1D [Mn(COO)(2)](n) chains. In 1 the chains are connected by the dicarboxylate ligands into a 3D framework with the pts topology, which is reinforced by interchain zipper-like pi-pi stacking arrays of the phen ligands. Differently, the chains in 2 are connected by the dicarboxylate ligands into 2D networks, which are pillared by the 4,4'-bipy ligands to generate a 3D framework with the new topology (4(4) x 6(2))(4(4) x 6(10) x 8). Compound 3 features double carboxylate bridged dimanganese(II) SBUs, which are connected by single mbpdc linkers and double bpee ones to give threefold interpenetrated 3D frameworks with the pcu topology. Magnetic investigations suggested 1 and 2 both exhibit weak antiferromagnetic exchanges mediated through the bis(syn-skew-carboxylate) bridges. (C) 2013 Elsevier B.V. All rights reserved.