Fabrication of Cu(II) based halobenzoate appended ladder polymers with efficient charge transport property

Two isotypical Cu(II) based one-dimensional coordination polymers (1D CPs) [{Cu2(p-clba)4(bpe)2}{Cu(p-clba)2(bpe)(CH3OH)}]n•1.25H2O (1) and [{Cu2(p-brba)4(bpe)2}{Cu(p-brba)2(bpe)(CH3OH)}]n•1.25H2O (2) (H2p-clba = para-chlorobenzoic acid, H2p-brba = para-bromobenzoic acid and bpe = 1,2-bis(4-pyridyl)ethylene) have been synthesized and characterized by X-ray structure analysis. In the solid-state strcuture, both the compounds undergo X•••п (X = Cl or Br) interactions to generate two-dimensional (2D) supramolecular architectures. Here, due to the larger size and more polarisability of Br atom, Br•••п interaction is stronger than Cl•••п, which is accounted for the stronger interchain interactions in 2 as compared to 1. This is depicted in the observed electrical conductivity of the compounds. The compound 2 with stronger interchain interactions shows better charge tranport and hence, increasing conductivity.