catena-Poly[[bis(pyridine-κN)zinc]-μ-5-carboxybenzene-1,3-dicarboxylato-κ2O1:O3]

Abstract

The title one-dimensional coordination polymer, [Zn(C9H4O6)(C5H5N)2]n or [Zn(HBTC)(py)2]n, (I), where BTC is benzene-1,3,5-tricarboxylate and py is pyridine, is a solvent-free polymorph of [Zn(HBTC)(py)2]·2C2H5OH [Yaghi et al. (1997). Chem. Mater. 9, 1074–1076]. Differences in the spatial arrangements and supramolecular packing of the [Zn(HBTC)(py)2]n chains in the two structures are described. The chain in (I) extends parallel to [100] and is severely puckered, with a Zn...Zn distance of 8.3599 (3) Å and a Zn...Zn...Zn angle of 107.516 (3)°, as a result of hydrogen-bonding interactions of the types O—H...O and C—H...O. There is no evidence for π–π interactions in (I). The differences between the solvent-free and solvent-containing structures can be accounted for by the absence of the ethanol solvent molecule and the use of the converging pair of O atoms in the bis-monodentate bridging HBTC2− ligand in (I).