A New Series of Cu<sup>II</sup> Coordination Polymers Derived from Bis-pyridyl-bis-urea Ligands and Various Dicarboxylates and Their Role in Methanolysis of Epoxide Ring-Opening Catalysis
2016-02-20T06:53:21Z (GMT) by
A crystal engineering approach has been adopted in synthesizing six new mixed ligand based Cu<sup>II</sup> coordination polymers (CPs) derived from two bis-pyridyl-bis-urea ligands, namely, <i>N</i>,<i>N</i>′-bis-(3-pyridyl)ethylene-bis-urea (<b>L1</b>) and <i>N</i>,<i>N</i>′-bis-(3-pyridyl)propylene-bis-urea (<b>L2</b>), and various dicarboxylates. The single crystal structures of the coordination polymers displayed diverse supramolecular architectures such as a one-dimensional (1D) chain, 1D-looped chain, and two-dimensional grid. Although none of them displayed an open-framework structure, which is believed to be conducive for heterogeneous catalysis, almost all of them showed moderate to excellent epoxide ring-opening catalysis. Powder X-ray diffraction indicated structural changes/degradation of the CPs, which might be generating substrate accessible Cu<sup>II</sup> species that presumably acted as the catalyst.