Supramolecular architecture of a novel salt of trimesic acid and 1,2-bis(4-pyridyl)ethane

Abstract

We report the transformation of [(BPEH₂)(H₂BTC)₂(H₃BTC)₂·(H₂O)] (I) (the first organic salt of trimesic acid with 1,2-bis(4-pyridyl)-ethane recently reported by us), into [(BPEH₂)₂(H₂BTC)₂(H₃BTC)₂·(H₂O)₁₄] (II), a new salt which was characterized structurally using single-crystal X-ray diffraction. II has increased crystal symmetry (monoclinic P2₁/n) when compared to I, and is formed by an extensive and very complex hydrogen bond network containing both homo- and heteronuclear neutral and ionic interactions. Water molecules play an important role in the hydrogen-bonding network, linking together adjacent zigzag ionic trimesic acid tapes leading to the formation of a 2D supramolecular anionic layer; connecting the BPEH₂²⁺ cations to the layers, and also acting as bridges between adjacent, close-packed layers.