One-pot synthesis of two new metal-organic networks: hydrogen bonded mononuclear Cu(II) complex and mixed-valence Cu(I,II) coordination polymer with encapsulated 14-membered unique water cluster

Abstract

{[Cu-4(mu-bpe)(4)Cu-2(mu-pydc)(2)(mu(3)-pydc)(2)]center dot 14H(2)O}(n) (1) and [Cu(pydcH)(2)(bpe)(2)] (2) have been solvothermally synthesized by 1,2-bis(4-pyridyl)ethylene (bpe) along with dianionic pyridine-2,3-dicarboxylate (pydc) ligands and characterized by elemental, FT-IR and thermal analyses techniques. In the solvothermal synthesis of complexes, 1 was isolated when the reactor was opened whereas 2 was crystallized after 3 weeks. The X-ray crystallographic studies show that complex 1 exhibits ladder-like structure involving mixed-valence Cu(I,II) which has generated a simultaneous in situ redox reaction and a unique 14-membered water cluster consisting of an eight-membered open-cube hexamer and two cyclic water trimers has been observed in hydrophilic cavities of 1. Supramolecular network of 2, which has proton transfer product of pydcH cations, is formed by O-H center dot center dot center dot N and aromatic interactions. (C) 2015 Elsevier B.V. All rights reserved.