Muconate bridged coordination polymers of Cu(II): Effect of auxiliary ligand on their structural architectures

Two coordination polymers [Cu2(2,2′-bpy)2(muco)2(H2O)2](H2O)2, (1) and [Cu(4,4′-bpy)(muco)(H2O)2], (2) [H2muco = trans,trans-muconic acid or 1,3-butadiene-1,4-dicarboxylic acid, 2,2′-bpy = 2,2′-bipyridyl and 4,4′-bpy = 4,4′-bipyridyl] have been synthesized by the reaction of muconate dianion with Cu(NO3)2·3H2O in presence of auxiliary ligands 2,2′-bpy and 4,4′-bpy respectively. Single crystal X-ray crystallographic structure determination reveals that 1 has one-dimensional (1D) structural motif and an extensive H-bonding pattern gives rise to 3D supramolecular network in the crystal of 1. On the contrary, 2 exhibits threefold interpenetrating three-dimensional (3D) net-work with CdSO4 topology. In the formation of these complexes, the auxiliary ligand has a vital role in directing the solid-state structure with defined topological network.

Effect of auxiliary ligands on the topology of network is illustrated in two Cu(II) complexes with a linear rigid dicarboxylate spacer in presence of two different auxiliary ligands. Chelating ligand furnished a 1D coordination polymer with extensive hydrogen bonding to form 3D hydrogen-bonded supramolecular architectures, whereas linear spacer ligand exhibits threefold interpenetrated 3D coordination polymer with CdSO4 topology (cds net).Figure optionsDownload as PowerPoint slideHighlights
► Effect of auxiliary ligands on the topology of network.
► X-ray crystallographic analysis of two new Cu(II) complexes.
► Chelating ligand furnishes hydrogen-bonded supramolecular architectures.
► Linear spacer ligand exhibits threefold interpenetrated cds net.