Control over the preparation of two pH-dependent Cu(ii) supramolecular isomers based on 1,3,5-benzenetricarboxylic acid and the bis(4-pyridylthio)methane ligand

Abstract

The possibility of controlling the formation of copper(II) coordination polymers based on the rigid carboxylate ligand 1,3,5-benzenetricarboxylic acid (H₃btc) and an N,N-divergent spacer with conformational flexibility, bis(4-pyridylthio)methane (SCS), was investigated. The new coordination polymers ¹_∞[Cu(H₂btc)₂(SCS)] (1) and ²_∞[Cu(Hbtc)(SCS)₂]·H₂O (2) have been prepared and characterized. Compounds 1 and 2 were obtained as a mixture and optimization of the synthetic conditions allowed the isolation of pure phases in high yield. Topological analysis showed the interpenetration of three networks with a vcm-type topology in 2. The thermal stability and the structural dynamics of these systems have also been investigated.